Wizarding numbers

[tobyreiner]

No: HPFGUIDX 81946

How many wizards are there in Harry Potter's Britain? 

I ask, because it seems to me that the population is barely adequate 
to cover the infrastructure detailed in the books. (Especially a 
Quidditch league)

According to an interview with Rowling, Hogwarts has 1,000 students; 
bearing in mind that there are only five boys in Gryffindor in 
Harry's year, this is about about three times more than I expected. 
If there were 10 per house per year, there would be 280 in the whole 
school. The discrepancy could be because Hufflepuff, as the only non-
selective house, is far bigger than the remaining three. 

Anyway, if there are 1,000 students in the school, there would 
normally be about 15,000 wizards and witches in the country, as it's 
the only school and would therefore include everyone in the 11-16 age 
range and, probably, most of the 16-18 year olds too. However, as 
wizards live longer than Muggles, maybe there are more. 

Does anyone know?