ggplot() geom_line

draw line graph.


## start of the code.

 x <- data.frame(
    year  = 1992:2019,
    CoefficientofVariation = as.vector(last(apply.monthly(SP5[,4],sd),325)[seq(1,325,12)]/last(apply.monthly(SP5[,4],mean),325)[seq(1,325,12)])
)
g <- ggplot(x, aes(x = year, y = CoefficientofVariation))
g <- g + geom_line()

plot(g)


## end of the code.