Not that you were asking me, but I can name seven off the top of my head (since 2000):
5 Indoor Track (00, 03, 05, 06, 13)
1 Outdoor Track (03)
1 Cross Country (00)
I am not sure about the girls, though. There could possibly be more.
I think I am remembering right, the men's programs have a total of 43 National Championships, after getting a few taken away in track a couple of years ago.
bp