A story in the campus paper gives some overall U of Oklahoma statistics (no individual chapter numbers, alas):
http://www.oudaily.com/news/2010/aug...g-recruitment/
"BY THE NUMBERS
847 — Women who participated in Open House
95 — Women who withdrew from rush
0.01% — Women who were released
722 — Women who pledged
85% — Women who pledged during rush
635 — Women who received their first-choice bid"