谁能帮我解决以下问题：
我想让第 3 和第 4 档的点位于绿松石箱线图“4 或更低”的中心。我怎样才能做到这一点？
mtcars$cyl = factor(mtcars$cyl)
mtcars$gear = factor(mtcars$gear)
mtcars$gear_binary = mtcars$gear
levels(mtcars$gear_binary) = c("4 or lower", "4 or lower", "5")
ggplot(data = mtcars, aes(x = cyl, y = mpg, fill = gear_binary)) +
geom_boxplot() +
geom_dotplot(aes(fill = gear), binaxis='y', stackdir='center', position = position_jitterdodge(0.25))