Its a region by region breakdown, complete with lots of cool charts. For example, in the 1950s, just over 1% of the NHL was from Atlantic Canada, a number which rose significantly in the 1960s.
I am not a NHL fan, I do not know the blogger at From the Rink, and I am not directing you to this blog because of some SBN directive. No, its just really interesting stuff, and if anything I wish these posts were longer. Once you read about, say, the rise of the Canadian Prairies, you'll want to see about New York, Alaska, etc etc.
If I knew how to do this for MLB I would. Well, maybe. Looks like a lot of work.