if there're 100 people taking an exam, and you are ranked 1st,
you're the 100th percentile.
if you are ranked 2nd, you're the 99th percentile.
if you are ranked 10th, you're the 90th percentile.
if you are ranked 90th, you're the 10th percentile.
so for poly to go uni, we look at the least, which is 10th
percentile?