With every server out their they claim the populaces to be the number of 'players' on at any given time. Every server out there has @autovend so it is safe to assume that there is usually 1 vender per 1 player. Yes there are some people who have more then that 1, but there are people out there who don't have one either. If you go to any other server and see their huge populace during peak time you can bet that half of them are vendors.