library(ggplot2)
library(gapminder)
library(readr)
library(dplyr)
## 
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
Skillsdrillz<-read.csv("/Volumes/NO NAME/Data 333/Practice Skills Drill 1 Data.csv")
head(Skillsdrillz)
##   year Behav_EverSmokeCigs_B Behav_CigsPerDay_N MentalHealth_MentalIllnessK6_C
## 1 1997                     0                  0                       Low Risk
## 2 1997                     0                  0                           <NA>
## 3 1997                     1                  5                       Low Risk
## 4 1997                     0                  0                       Low Risk
## 5 1997                     0                  0                       Low Risk
## 6 1997                     1                  0                            MMD
Skillsdrillz %>%
  select(year,Behav_CigsPerDay_N) %>%
  rename(NumCigs = Behav_CigsPerDay_N) %>%
  filter(year>"1997") %>%
  mean(NumCigs)
## Warning in mean.default(., NumCigs): argument is not numeric or logical:
## returning NA
## [1] NA
Skillsdrillz %>%
  select(year,Behav_CigsPerDay_N) %>%
  rename(NumCigs = Behav_CigsPerDay_N) %>%
  group_by(year)%>%
  filter(year>"1997") %>%
  summarize(NumCigs=mean(NumCigs))
## # A tibble: 19 x 2
##     year NumCigs
##    <int>   <dbl>
##  1  1998    3.83
##  2  1999    3.57
##  3  2000    3.48
##  4  2001    3.43
##  5  2002    3.29
##  6  2003    3.09
##  7  2004    2.92
##  8  2005    2.88
##  9  2006    2.74
## 10  2007    2.47
## 11  2008    2.67
## 12  2009    2.49
## 13  2010    2.32
## 14  2011    2.32
## 15  2012    2.23
## 16  2013    2.08
## 17  2014    1.99
## 18  2015    1.87
## 19  2016    1.95

Interpretation

Skillsdrillz %>%
  select(year,Behav_CigsPerDay_N) %>%
  rename(NumCigs = Behav_CigsPerDay_N) %>%
  group_by(year)%>%
  filter(year>"1997") %>%
  summarize(NumCigs=mean(NumCigs))%>%
  ggplot() +
  geom_line(aes(x=year,y=NumCigs, color=NumCigs))