I'm quite new in R, but I'm trying to do a facet_grid using ggplot package in R and, for better data visualization, I'd like to insert the percentage of values in each quadrant for the column groupings, like the image below:

Can be one or another, in each quadrant or in legend.
My code is this one below
ggplot(df1_final,aes(x=revenue,y=visits,col=groupings)) +
  geom_jitter(alpha=I(1/2)) + 
  xlim(c(0,20000)) + 
  facet_grid(group_lvl_1_visits ~ group_lvl_1_revenue)
Could anyone help me on this?
EDIT: Both solutions helped me a lot, very good ones.
 
     
    

 
    
