You'd be surprised, especially since the security wasn't as tight to keep them out. There aren't as many archeologists or anthropologists as they are other types of researchers out there.
edit: corrected a number. Also, I looked at "employed" meaning full time or part time research vs. just having a PhD in it. Like physics PhDs are 58K which sounds about right, just few actually get a faculty position, temporary (post-doc, staff scientist) or otherwise.
As for why I say both, the number of positions tends to also put downward pressure on number of applicants I think and makes it more likely people who study it or consider studying it consider other fields or jobs before even applying.