# Standardize numbers for ranking ratios

I'm trying to rank some percentages. I have numerators and denominators for each ratio. To give a concrete example, consider ratio as total graduates / total students in a school.

But the issue is that total students vary over a long range (1000-20000). Smaller schools seem to have higher percentage of students graduating, but I want to standardize it, and not let the size of the school affect the ranking. Is there a way to do it?