I don't unfortunately have that off-hand. There was a study a while ago that looked at schools where the students were primarily of different European group descents. Googling for it doesn't turn up anything (unfortunately the obvious keywords are drowned out by many other articles looking at similar sorts of stuff for blacks and other groups). Glados linked to data below that if anything actually goes against this sort of claim a fair bit, so I'm going to withdraw it until I can find something.
Post by fellow LW reader Razib Khan, who many here probably know from the gnxp site or perhaps from his debate with Eliezer.