I have lately been doing a lot of thinking about the enrollment numbers at Hogwarts. In Harry's class, we estimate that his class size was at about thirty, but also keep in mind, this was when Voldemort's reign was at it's peak, so I imagine having children wasn't really a top priority for a lot of people, or at least more than one child (don't know what was happening with the Weasleys, or if they'll just survive nuclear war along with the cockroaches).

But anyway, do you see there being a noteable birthrate change between times when Voldemort was reigning and in times of peace?