I find these two structures in the same book:
the figure/percentage/total, etc. FOR a group or category
Ex: If we compare the percentages FOR skilled and unskilled workers...
But on a different page, it has sentences like this
The chart shows the percentage OF households with more than one car.
The percentage OF students with blue eyes is 25%.
So, what is the difference here? Is it possible to write: "If we compare the percentages OF skilled and unskilled workers"? Please help me, thank you.