By IP address, email addresses aren’t actually required to sign up.
I haven’t looked at those numbers for new users specifically, but I’d imagine they are roughly in line with our site stats overall, which in summary is 35% from the US, 8% from the rest of the America’s, 34% from Europe, 6% from Russia, 15% from Asia, and 2% from Oceania+Africa. I’ve never looked at email domain distribution.