Can't really say I know exactly how many in my neck of the woods....
As the township I live in, Hamilton Twp, NJ (yes, the doggone post office with the anthrax mess!- try not getting mail for 3 days, but that's another thread) - there are about 90000 people in Hamilton. Then you have all your other Townships that run into Hamilton, -- Lawrence, Ewing, Princeton, Washington, Trenton City, Hopewell. I do drive a lot for work, and I do count how many MDX's I see on any given day! The most I think was 4, although I did follow a SS one into LBI yesterday!!!
Nan