How To Turn Bar Chart Into Stacked Chart

I have a two bar chart (red and blue) I'm trying to turn into a stacked chart. It has total cars and broken cars. There are a 100 total cars (10 broken). But when I stack them, it shows 110 total cars (it's adding instead of merging them). Once stacked, there should still be 100 total cars....but the tip of it should be red to show what amount is broken. It's adding the two together but it shouldn't....the number of broken cars is still part of the total.