Baltimore emissions of PM 2.5 1999 TO 2008 There was a slight reduction in the emissions

library(ggplot2)
library(dplyr)
library(plotly)
setwd('D:/Documents and Settings/tnjunge/Documents/R/Exploratorydatanalysisdata')
NEI <- readRDS("summarySCC_PM25.rds")
SCC <- readRDS("Source_Classification_Code.rds")
SCC_motor <- grep("motor", SCC$Short.Name, ignore.case = TRUE)
SCC_motor <- SCC[SCC_motor, ]
SCC_code <- as.character(SCC_motor$SCC)
NEI$SCC <- as.character(NEI$SCC)
NEI_motor <- NEI[NEI$SCC %in% SCC_code, ]
NEI_motorbalt<- NEI_motor[which(NEI_motor$fips == "24510"), ]
NEI_motorbalt <- with(NEI_motorbalt, aggregate(Emissions, by = list(year), 
                                                         sum))