Click the population of the highlighted state. PLEASE use the random order thing, or else it will be way too easy for you, you would just have to click at the bottom and go up. Using fixed order would be cheating. Thanks and pls subscribe :)
Interesting idea. Do you know that you can just start at the bottom and then click upwards for 100% (unless you slip, like me, and get three wrong answers before you see what you've done)?