Does Brookfield Zoo (Chicago) get crowded on Easter Sunday?

Hey all! I know that this may not be able to be answered 100% accurately, because there may be other factors that affect this (i.e. weather, etc), but can anyone tell me if, in general, Easter Sunday is a busy/crowded day at Brookfield Zoo In Chicago? I know that they do a big brunch there on Easter, but we do not plan to go to that. We only want to visit the zoo & plan on being there when they open at 10:00 am. Any thoughts or suggestions are appreciated. Thanks!