How many muggleborns are there in any given year? I never kept track. Training them is going to be rather the undertaking with the numbers we have, though. We'll need to start going out for supplies sooner rather than later if there are many left.
Regulus/Remus Now, now, Harry's been here a week less than the rest of us. So, it doesn't really count as faster than him.
But, I will give you that you thought of it faster than the rest of us who arrived that first day.