R histogram add label with percentage instead of rough values

I want to use hist() to make a histogram using percentages.

However, I also want to place a label at the top of each histogram bar showing the actual percentage.

Here is my code and a link to the output:

DataToPlot <- sapply(dataframe, as.numeric)

hist(DataToPlot, xlab="dataframe",ylab="Calls", main="Weekly data", col="lightgreen",labels = TRUE, ylim=c(0, 12000))