Note that that number is just a guess; if you check the site's statistics accuracy page (it's actually pretty funny), you'll see that there are several factors that might result in the numbers being quite a bit higher or lower than they should be. Most importantly, the original data left out all names that didn't occur often enough (which ended up being about 10% of the total data) so relatively rare given names or surnames (or both) will come up with 0, even if you know there's a baker's dozen of you out there, because the U.S. Census was looking to report on every Tom, Dick, and Harry, but not necessarily every Szandor, Issur, and Neela.
Freudalism: Serf & Mom