A Math Problem

I ran across this problem somewhere on the internet and I don't remember where.

Imagine a country where the custom is that the last child should be a boy. If two parents have a boy then they stop having more children. If they have a girl, then they may continue and have more kids until they have a boy. Here is the question: long term, what is the male/female breakdown of the population?

Leave your answers in the comment section.

(When I mentioned this to the FP Gal we actually flipped coins and charted twenty families. That's why I love her!)