You want to graph the empirical cumulative distribution function (ECDF) of a data set.

Use stat_ecdf() (Figure 13-26):

library(gcookbook) # For the data set

# ecdf of heightIn
ggplot(heightweight, aes(x=heightIn)) + stat_ecdf()

# ecdf of ageYear
ggplot(heightweight, aes(x=ageYear)) + stat_ecdf()

Figure 13-26. Left: ECDF of height; right: ECDF of age

The ECDF shows what proportion of observations are at or below the given x value. Because it is empirical, the line takes a step up at each x value where there are one or more observations.