For you non-hoosiers, here's a link to an article and overview of the race's 50 years.
http://www.indiana.edu/~alumni/magta...little500.html
Looking at the list of '02 entrants, I see only about 10-12 fraternities out of 33.
I wish some of the current hoosier undergrads would post on how the declining number of Greek teams affects Greek interest in the race.