Introduction

In recent decades, society has been the victim of one of the worst scourges: terrorism, which is an expressive fact of violence that can be seen throughout history with its most varied forms of expression and cruelty. Numerous terrorist incidents within the hemisphere during the last years have shown that terrorism is an extreme and constant danger for local and worldwide peace. This phenomenon is one of the most difficult forms of violence to contain because its scope extends beyond the regions of conflict. It is a phenomenon characterized by its indiscriminate violence which involves victims who have nothing to do with the conflict that caused the terrorist act. Its unpredictability acts by surprise creating uncertainty and instilling terror on people. The consequences of those activities for the safety of human rights and democracy are extraordinarily critical and require immediate and rigorous consideration by means of the global community, such as the Organization of American States. As this commission has reiterated, international law obliges the member states to adopt the essential measures to prevent terrorism and other forms of violence and to assure the security in their residents.

Abstract

The Global Terrorism Database (GTD) was developed to be a comprehensive, methodologically robust set of longitudinal data on incidents of domestic and international terrorism. Its primary purpose is to enable researchers and analysts to increase understanding of the phenomenon of terrorism. The GTD is specifically designed to be amenable to the latest quantitative analytic techniques used in the social and computational sciences.

The GTD was designed to gather a wide variety of etiological and situational variables pertaining to each terrorist incident. Depending on availability of information, the database records up to 120 separate attributes of each incident, including approximately 75 coded variables that can be used for statistical analysis.

Resources

https://www.start.umd.edu/gtd/

Research Question

For this project, the main goal is to summarise the data pertaining to terrorist attacks in order to explain the proportional effect of terrorism in the world as well as the major trends related to their activities.

Data Preparation

This sections defines basic cleaning operations. Other cleaning tasks are going to be performed as needed accross the sections.

Loading the dataset.

terror_dt <- read.csv("globalterrorismdb_0718dist.csv", stringsAsFactors = TRUE)

Loading world map dataset for ploting later.

world_dt <- map_data("world") %>% fortify()
map_locations <- terror_dt[(!is.na(terror_dt$latitude) & !is.na(terror_dt$longitude)),]

Filling Values for Columns representing the number of victims and injured where Na values suggest that no victims where recorded, therefore, we assume that there were no victims or injured

terror_dt$nkill %<>% replace_na(0) 
terror_dt$nwound %<>% replace_na(0) 

Exploratory Analysis

In this section, we are going to observe what are the facts and trents that are stated in the Global Terrorism dataset.

World Map of Terrorist Attacks

This world map illustratres all the places around the world were incidents classified as terrorist attack due to a especific criteria.

locations <- geom_point(data = map_locations,aes(x = longitude,y = latitude,color=region_txt),size=1)


world_plot <- ggplot()+geom_polygon(
  data = world_dt,
  aes(x = long,
      y = lat,
    group=group,
    map_id=region),
  fill="#4B535D",
  colour="white",
  size=0.1)+xlim(-170,190)+ylim(-60,90)+ggtitle("World Map of terrorist Incidents from 1970 to 2017")+xlab("Longitude")+ylab("Latitude")+theme(legend.title = element_blank(),legend.position = "bottom",panel.background = element_rect(fill="#CCD3D3"),panel.grid.major = element_blank(),panel.grid.minor = element_blank(),legend.text = element_text(size = 13))

world_plot+locations

As a quick reference, each region in the world map groups the following countries:

North America: includes countris such as Canada, Mexico, United States.

Central America & Caribbean: includes countries such as Antigua and Barbuda, Bahamas, Barbados, Belize, Cayman Islands, Costa Rica, Cuba, Dominica, Dominican Republic, El Salvador, Grenada, Guadeloupe, Guatemala, Haiti, Honduras, Jamaica, Martinique, Nicaragua, Panama, St. Kitts and Nevis, St. Lucia,Trinidad and Tobago

South America: include countries such as Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Falkland Islands, French Guiana, Guyana, Paraguay, Peru, Suriname, Uruguay, Venezuela

East Asia: includes China, Hong Kong, Japan, Macau, North Korea, South Korea, Taiwan

Southeast Asia: includes Brunei, Cambodia, East Timor, Indonesia, Laos, Malaysia, Myanmar, Philippines, Singapore, South Vietnam, Thailand, Vietnam

South Asia: includes Afghanistan, Bangladesh, Bhutan, India, Maldives, Mauritius, Nepal, Pakistan, Sri Lanka

Central Asia: includes Armenia, Azerbaijan, Georgia, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan

Western Europe: includes Andorra, Austria, Belgium, Cyprus, Denmark, Finland, France, Germany, Gibraltar, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom, Vatican City, West Germany (FRG)

Eastern Europe: includes Albania, Belarus, Bosnia-Herzegovina, Bulgaria, Croatia, Czech Republic, Czechoslovakia, East Germany (GDR), Estonia, Hungary, Kosovo, Latvia, Lithuania, Macedonia, Moldova, Montenegro, Poland, Romania, Russia, Serbia, Serbia- Montenegro, Slovak Republic, Slovenia, Soviet Union, Ukraine, Yugoslavia

Middle East & North Africa: includes Algeria, Bahrain, Egypt, Iran, Iraq, Israel, Jordan, Kuwait, Lebanon, Libya, Morocco, North Yemen, Qatar, Saudi Arabia, South Yemen, Syria, Tunisia, Turkey, United Arab Emirates, West Bank and Gaza Strip, Western Sahara, Yemen

Sub-Saharan Africa: includes Angola, Benin, Botswana, Burkina Faso, Burundi, Cameroon, Central African Republic, Chad, Comoros, Democratic Republic of the Congo, Djibouti, Equatorial Guinea, Eritrea, Ethiopia, Gabon, Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Kenya, Lesotho, Liberia, Madagascar, Malawi, Mali, Mauritania, Mozambique, Namibia, Niger, Nigeria, People’s Republic of the Congo, Republic of the Congo, Rhodesia, Rwanda, Senegal, Seychelles, Sierra Leone, Somalia, South Africa, South Sudan, Sudan, Swaziland, Tanzania, Togo, Uganda, Zaire, Zambia, Zimbabwe

Australasia & Oceania: includes Australia, Fiji, French Polynesia, New Caledonia, New Hebrides, New Zealand, Papua, New Guinea, Solomon Islands, Vanuatu, Wallis and Futuna

Incidents by country

As shown in the graph, the higer number of incidents in the world belong to Iraq from Middle East & North Africa, followed by countries such as Pakistan, Afganistan, the India from South Asia and Colombia from South America.

terror_no <- terror_dt %>% group_by(country_txt) %>% tally(name = "attacks",sort = TRUE)

terror_no_plt <- terror_no %>% top_n(20) %>% ggplot(aes(x = fct_reorder(country_txt,attacks),y = attacks,fill=country_txt))+geom_bar(stat = "identity")+coord_flip()+theme(legend.position = "none")+ggtitle("Top 20 of countries with more incidents")+xlab("countries")+geom_text(aes(label=attacks), hjust=1)


terror_no_plt

The table below summarises the number of attacks by country.

datatable(terror_no,colnames = c("Rank","Country","Number of Attacks"),caption = "Table 1: Number of incidents for each country from 1970 to 2017")

Cities in the World

The following graph represents the cities in the world with the higer number of incidents. Baghdad and Mosul in Iraq, Karachi in Pakistan, Lima in Peru, and Belfast in the United Kingdom are the cities in the world witht the top five places of terrorist incidents.

city_no <- terror_dt %>% select(city,region_txt,country_txt) %>% group_by(city,region_txt,country_txt) %>% tally(name = "count",sort = TRUE) %>% ungroup()


city_no[city_no$city!="Unknown",] %>% top_n(20) %>%  ggplot(aes(x = fct_reorder(city,count),y = count,fill=region_txt))+geom_bar(stat = "identity")+coord_flip()+theme(legend.title = element_blank(),legend.position = "bottom")+ggtitle("Top 20 of Cities in the World with more Incidents")+xlab("countries")

The table below summarises the number of incidents for a particular city in the world organized by the number of attacks.

city_incidents <- city_no[city_no$city != "Unknown",]

datatable(city_incidents,colnames = c("Rank","Country","Region","Number of Attacks"),caption = "Table 2: Cities in the world with more incidents")

Incidents by year

As show in the graph, the number of terrorist incidents started to increase dramatically reaching a high number of incidents between 2003 and 2015 after a trough before 1997.

#Number of attacks for earch region during since 1970 to 2017
attack_tml <- terror_dt %>% group_by(region_txt,iyear) %>% tally(name = "incident_no")

#######

atk_tml_plt <- attack_tml %>% ggplot(aes(x = iyear,y = incident_no,group=region_txt,color=region_txt))+geom_line()+ggtitle("Number of Incidents by year")+ylab("Number of Incidents")+xlab("Year")+labs(colour="Region")+scale_x_discrete(breaks=seq(1970,2017,by=5),limits=1970:2017)+theme(legend.position = "bottom",legend.text = element_text(size = 12))

atk_tml_plt

atk_tml_plt+facet_wrap(region_txt~.,scales = "free_y",ncol = 2)+theme(legend.position = "none")

  • Central Asia had experience a maximum of 80 incidents in 1992. after that, the number of incidents have been decreasing with some light increases in the number of incidents until 2017.

  • Sub-Sahara Africa had a number of incidents that did not passed the threshold of 500 from 1970 to 2010. After that the number of incidents started to increase reaching a number grater than 1500 incidents for the rest of the years.

  • North America, from 1970 to 1973 seemed to be years of high terrorist activity, however, it started to decrease intil it reaches a certain level of estability from 1974 to 2017.

  • From 1975 to 2000 in Central America & Caribbean, the activity of terrorism was relatively high, however, the activity of incidents decreased to near 0 for the last years.

  • South America Experienced high level of terrorist activity until 2000, then the levels of incidents decreased and keep a somewhat normal level of activity.

  • Australia and Oceania had an active level of incidents from 1970 to 2017, however, the maximum number of incidents that happened during those years is 30; therefore, it is verylow compared to other regions of the world.

Fatalities by Region

This section includes the number of victims and attackers who died as a direct result of the incident. Where there is evidence of fatalities, but a figure is not reported or it is too vague to be of use, this field is counted as 0. If information is missing regarding the number of victims killed in an attack, but perpetrator fatalities are known, the number of victims will reflect only the number of perpetrators who died as a result of the incident and viceversa.

#Number of kills for earch region during since 1970 to 2017
victim_tml <- terror_dt %>% select(region_txt,nkill,iyear) %>% group_by(region_txt,iyear) %>% summarise(victims=sum(nkill)) %>% ungroup()


#victim_tml$victims[is.na(victim_tml$victims)] <- 0
tml <- victim_tml%>% ggplot(aes(x = as.numeric(iyear),y = victims,group=region_txt))+geom_line(aes(color=region_txt))+theme(axis.text.x = element_text(angle = 50),legend.position = "bottom",legend.text = element_text(size = 10))+scale_x_discrete(breaks=seq(1970,2017,by=5),limits=1970:2017)+xlab("years")+ggtitle("Victims Timeline")

tml

Detailed View

tml+facet_wrap(.~region_txt,ncol = 1, scales = "free_y")+theme(legend.position = "none",panel.spacing = unit(3,"line"))

nkill_summary <- terror_dt %>% group_by(region_txt) %>% select(region_txt,nkill,city)


nkill_summary %<>% summarise(total_kill=sum(nkill)) %>% mutate(proportion=round(total_kill/sum(total_kill)*100,3))

nkill_summary %<>% mutate_if(is.character,as.numeric)
nkill_summary %<>% mutate_if(is.factor,as.character)

nkill_summary %<>% rbind(c("Total",apply(nkill_summary[,2:3],2,sum)))
nkill_summary  %>% 
  kable(col.names = c("Region","Fatalities Number","World Percentaje"),caption = "Table 3: Number of fatalities from 1970 to 2017") %>% 
  kable_styling(position = "center",full_width = F,bootstrap_options = "striped",font_size = 13)
Table 3: Number of fatalities from 1970 to 2017
Region Fatalities Number World Percentaje
Australasia & Oceania 150 0.036
Central America & Caribbean 28708 6.97
Central Asia 1000 0.243
East Asia 1152 0.28
Eastern Europe 7415 1.8
Middle East & North Africa 137642 33.419
North America 4916 1.194
South America 28849 7.004
South Asia 101319 24.6
Southeast Asia 15637 3.797
Sub-Saharan Africa 78386 19.032
Western Europe 6694 1.625
Total 411868 100

Number of Injured

This section records the number of confirmed non-fatal injuries to both perpetrators and victims around the world

#Number of people injured for earch region during since 1970 to 2017
injured_tml <- terror_dt %>% select(region_txt,nwound,iyear) %>% group_by(region_txt,iyear) %>% summarise(injured=sum(nwound)) %>% ungroup()
injured_tml %>% ggplot(aes(y = injured,x = iyear,group=region_txt,color=region_txt))+geom_line()+theme(axis.text.x = element_text(angle = 50),legend.position = "bottom",legend.text = element_text(size = 10),legend.title = element_blank())+scale_x_discrete(breaks=seq(1970,2017,by=5),limits=1970:2017)+xlab("years")+ggtitle("Number of Injured People over the Years")

As shown in the graph above, the number of injured due to terrorism from 1990s to 2017 started to reach higer peaks compared to previous years

wound_summary <- terror_dt %>% group_by(region_txt) %>%
  summarise(totalw=sum(nwound)) %>% 
  mutate(proportion=round(totalw/sum(totalw)*100,3))



wound_summary %<>% mutate_if(is.character,as.numeric)
wound_summary %<>% mutate_if(is.factor,as.character)

wound_summary %<>% rbind(c("Total",apply(wound_summary[,2:3],2,sum)))


wound_summary   %>% 
  kable(col.names = c("Region","Injured Number","World Percentaje"),caption = "Table 4: Number of injured from 1970 to 2017 for each region of the world") %>% 
  kable_styling(position = "center",full_width = F,bootstrap_options = "striped",font_size = 13)
Table 4: Number of injured from 1970 to 2017 for each region of the world
Region Injured Number World Percentaje
Australasia & Oceania 260 0.05
Central America & Caribbean 8991 1.716
Central Asia 2009 0.383
East Asia 9213 1.759
Eastern Europe 12045 2.299
Middle East & North Africa 214308 40.909
North America 21531 4.11
South America 16704 3.189
South Asia 141360 26.984
Southeast Asia 26259 5.013
Sub-Saharan Africa 52857 10.09
Western Europe 18332 3.499
Total 523869 100.001

Targets of Terrorism

This sections shows the general type of target or victim. When a victim is attacked specifically because of his or her relationship to a particular person, such as a prominent figure, the target type reflects that motive. For example, if a family member of a government official is attacked because of his or her relationship to that individual, the type of target is “government.”

This variable consists of the following 22 categories which are shown in the following graphs which display the occurence of incidents categorized according to the type of target that terrorist wanted to reach by region.

targets <- terror_dt %>% select(targtype1_txt,nkill,region_txt) %>% group_by(targtype1_txt,region_txt) %>% tally(name = "incidents_no",sort = TRUE)


targets %>% ggplot(aes(x = region_txt,y = incidents_no,fill=targtype1_txt))+geom_bar(stat = "identity")+coord_flip()+facet_wrap(.~ targtype1_txt,ncol = 1,scales = "free_x")+theme(legend.position = "none",plot.background = element_rect(fill = "transparent",colour = NA)
)+xlab("")+ylab("")+ggtitle("Incident Type Occurence by Region from 1970 to 2017")

This table summarises the proportion of attacks around the world targeted to an especific type of victim.

total_target <- targets$incidents_no %>% sum()


target_summary <- targets %>% 
  spread(key = region_txt,value = incidents_no, fill = 0) %>% ungroup() 



target_summary[,2:length(target_summary)] <- round((target_summary[,2:length(target_summary)]/total_target)*100,3)

target_summary %<>%  mutate(Total=rowSums(.[2:13]))

target_summary[[1]] <- target_summary[[1]] %>% as.character()


total <- c("Total",apply(target_summary[,2:14], 2,FUN = sum))

target_summary <- target_summary %>% rbind(total)
header <- names(target_summary) %>% unlist()
header[1] <- "Region"
target_summary %>% 
  kable(caption = "Table 5: Proportion of Incidents by Region",col.names = header) %>% 
  kable_styling(position = "left",full_width = F,bootstrap_options = "striped",font_size = 13) %>% scroll_box(width = "100%")
Table 5: Proportion of Incidents by Region
Region Australasia & Oceania Central America & Caribbean Central Asia East Asia Eastern Europe Middle East & North Africa North America South America South Asia Southeast Asia Sub-Saharan Africa Western Europe Total
Abortion Related 0 0 0 0 0 0 0.142 0.001 0 0 0 0.002 0.145
Airports & Aircraft 0.004 0.041 0.003 0.032 0.017 0.152 0.031 0.08 0.096 0.028 0.073 0.182 0.739
Business 0.025 0.656 0.019 0.056 0.239 2.289 0.498 1.923 1.719 0.951 0.685 2.317 11.377
Educational Institution 0.004 0.113 0.004 0.008 0.032 0.451 0.098 0.195 0.98 0.225 0.171 0.098 2.379
Food or Water Supply 0.001 0.009 0.001 0.001 0.005 0.03 0.004 0.044 0.035 0.013 0.025 0.008 0.176
Government (Diplomatic) 0.017 0.121 0.018 0.019 0.075 0.44 0.101 0.215 0.166 0.068 0.356 0.372 1.968
Government (General) 0.029 0.611 0.069 0.07 0.383 2.342 0.228 1.568 3.007 1.083 1.136 1.187 11.713
Journalists & Media 0.002 0.15 0.012 0.01 0.069 0.375 0.067 0.321 0.241 0.091 0.124 0.161 1.623
Maritime 0.001 0.021 0.001 0.002 0 0.031 0.004 0.017 0.027 0.041 0.035 0.013 0.193
Military 0.008 1.687 0.05 0.022 0.625 5.102 0.116 0.974 3.135 1.259 1.663 0.761 15.402
NGO 0.001 0.014 0.006 0.001 0.021 0.074 0.019 0.032 0.163 0.024 0.154 0.026 0.535
Other 0 0.002 0 0 0.003 0.046 0.001 0.001 0.009 0.005 0.003 0.006 0.076
Police 0.018 0.321 0.042 0.054 0.482 3.794 0.129 1.242 4.662 0.742 0.824 1.177 13.487
Private Citizens & Property 0.02 0.826 0.043 0.053 0.474 8.397 0.258 1.735 5.774 1.377 3.147 1.844 23.948
Religious Figures/Institutions 0.015 0.047 0.004 0.018 0.097 0.695 0.094 0.192 0.628 0.188 0.296 0.17 2.444
Telecommunication 0.001 0.083 0.003 0.003 0.009 0.039 0.006 0.079 0.167 0.086 0.036 0.046 0.558
Terrorists/Non-State Militia 0 0.019 0.005 0.003 0.01 0.936 0.004 0.043 0.384 0.043 0.079 0.147 1.673
Tourists 0.001 0.009 0.001 0.002 0.005 0.08 0.007 0.021 0.028 0.019 0.019 0.051 0.243
Transportation 0.006 0.223 0.019 0.081 0.162 0.653 0.021 0.594 1.162 0.254 0.319 0.247 3.741
Unknown 0.001 0.046 0.006 0.003 0.07 1.189 0.008 0.091 1.322 0.161 0.143 0.207 3.247
Utilities 0.002 0.675 0.005 0.003 0.047 0.447 0.057 1.062 0.44 0.21 0.261 0.105 3.314
Violent Political Party 0.002 0.017 0 0.001 0.004 0.219 0.009 0.015 0.609 0.007 0.113 0.032 1.028
Total 0.158 5.691 0.311 0.442 2.829 27.781 1.902 10.445 24.754 6.875 9.662 9.159 100.009


Based on the summary, we can state the following facts.

  • 11.37% of the terrorist attacks in all of its varieties are targeted to business. which includes attacks carried out against corporate offices or employees of firms like mining companies, or oil corporations. Furthermore, includes attacks conducted on business people or corporate officers. Included in this value as well are hospitals and chambers of commerce and cooperatives.

  • 11.71% of the terrorist attacks are targeted to any government member,member, former members, including members of political parties in official capacities, their convoys, or events sponsored by political parties; political movements or a government sponsored institution where the attack is expressly carried out to harm the government.

  • 23.94% of the attacks in the world includes attacks on individuals, the public in general or attacks in public areas including markets, commercial streets, busy intersections and pedestrian malls.

  • 15% of the attacks in the world includes attacks against military units, patrols, barracks, convoys, jeeps, and aircraft.

  • 13% of the attacks in the world are targeted to members of the police force or police installations; including police boxes, patrols headquarters, academies, cars, checkpoints, etc. Includes attacks against jails or prison facilities, or jail or prison staff or guards.

  • Other type of targets such as Abortion Related, Airports & Aircraft, Educational Institution, Food or Water Supply, Government (Diplomatic), Journalists & Media, Maritime, etc…, are less likely to be targeted with probabilities less than 4%.

With the regards to the three most active regions of the world, Middle East & North Africa have the higer number of incidents with 27.78% of the attacks that happen in the world, South Asia follows with a 27.7% and finally South America with a 10.44%.

Type of Attacks

This Section shows the general method of attack class of tactics used. It consists of nine categories, which are defined below. Only one attack type is recorded for each incident unless the attack is comprised of a sequence of events. Attacks are also recorded based on the goal, not the method used. For example, if an assassination is carried out through the use of an explosive, the Attack Type is coded as Assassination, not Bombing/Explosion.

atk_type <- terror_dt %>%
  select(attacktype1_txt,region_txt) %>%
  group_by(attacktype1_txt,region_txt) %>% tally(name = "attack_no")
atk_type %>% ggplot(aes(y = attack_no,x = fct_reorder(region_txt,attack_no), fill=attacktype1_txt))+geom_bar(stat = "identity"  )+theme(axis.text.x = element_text(angle = 40,vjust = 0.8,hjust = 1))+facet_wrap(.~attacktype1_txt,nrow = 3,scales = "free_x")+coord_flip()+ggtitle("Type of Attacks by Region")+xlab("Number of Attacks")+ylab("Number of Deaths")+theme(legend.position = "none")

Table summary by region

atk_type_summary <- atk_type %>% spread(key = attacktype1_txt,value = attack_no)
atk_type_summary %>%
  kable(col.names = c( "Region","Armed Assault", "Assassination","Bombing/Explosion","Facility/Infrastructure Attack" ,  "Hijacking","Hostage Taking (Barricade Incident)", "Hostage Taking (Kidnapping)", "Unarmed Assault","Unknown"    ),caption = "Table 6: Summary of incidents by Region") %>% 
 kable_styling(position = "left",full_width = F,bootstrap_options = "striped",font_size = 13) %>% scroll_box(width = "100%")
Table 6: Summary of incidents by Region
Region Armed Assault Assassination Bombing/Explosion Facility/Infrastructure Attack Hijacking Hostage Taking (Barricade Incident) Hostage Taking (Kidnapping) Unarmed Assault Unknown
Australasia & Oceania 51 36 75 71 3 6 13 11 16
Central America & Caribbean 4361 1254 3239 403 26 187 501 19 354
Central Asia 116 115 235 20 8 2 45 5 17
East Asia 117 55 330 200 18 3 14 42 23
Eastern Europe 1274 400 2766 260 26 21 220 62 115
Middle East & North Africa 9273 4206 30908 1115 138 100 2666 177 1891
North America 448 255 1534 906 18 67 123 73 32
South America 3875 2745 9039 803 67 234 1414 47 754
South Asia 11404 4301 21246 2189 93 120 3277 323 2021
Southeast Asia 4022 1369 4818 948 59 67 744 25 433
Sub-Saharan Africa 6004 1638 5557 810 136 95 1872 83 1355
Western Europe 1724 2938 8508 2631 67 89 269 148 265

Conclusion

Based on the data we can conclude that incidence of terrorism around the world have, in overall, increased with the pass of the years, however, such changes are relative to the regions where the incidences took places since increases in the terrorism incidents in certaing regions of the world despite high, does not compare to other regions of the world.

As a matter of fact, the higer total number of victims around the world are located in the Middle East & North Africa which represents a 33.41% of the world wide victims whereas the Sub-Saharan Africa region and South America represents the 19.04% and the 7% of the world wide victims respectively. On the other hand, contrary to popular believes, regions like North America
and Europe (West and East) represent only a 1.2% and a 3.4% of all the incidents around the world.

Since the data is continously modified in order to increase the accuracy of the information about certain incidents, in the future I expect the get more data in order to calculate better proportion estimates for the incidents that happened between 1970 and 2017 and possibly 2018.