Here's an article from 2005 about Spring Rush at UGA but I can't find anything more recent.
http://media.www.redandblack.com/med...-2573196.shtml
Not every house participates. The one I advise has not participated in Spring Rush in 20+ years.
And FYI-- House Total at UGA is at 170. The UGA panhellenic just voted NOT to increase to 180.
As of the end of Fall recruitment, not counting any COB numbers, the only two houses under 170 were Delta Gamma and Sigma Delta Tau. So they would be the only two participants in Spring Rush.