library(tidyverse)

x <- c(20, 28, 30, 35, 41, 50, 51, 57, 60, 65,
       66, 70, 71, 71, 75, 78, 80, 80, 81, 82,
       84, 85, 85, 86, 87, 90, 91, 94, 95, 98,
       99, 100, 100)

df <- data.frame(x)

# density curve
ggplot(df, aes(x = x)) +
geom_density() +
geom_rug() # shows the raw scores on the x-axis

# cumulative density curve

ggplot(df, aes(x = x)) +
   stat_ecdf(geom = "smooth")