Given that you're only getting dozens of replies, why are you asking for institution? The only useful pattern I can think of would be something like correlating against university ranking, but that doesn't sound too useful.

I was thinking I'd start with a "places most of us have heard of" (Oxford, Cambridge, Harvard, MIT, Stanford, etc.) vs. "everywhere else" comparison. I'm at somewhere over 100 replies at this point, so I imagine I'll have enough data for that sort of comparison to be meaningful.