Typically, 60-80% of graduates get in somewhere. I've had mixed success finding the information on a school-by-school basis (and I'm sure the numbers on the schools' websites might be inflated).
Anyway, as far as UPenn goes, it heavily depends on which program you're in. If you are specialized studies you can only link into two schools. If you are generic pre-health you can link into eight.
http://www.sas.upenn.edu/lps/postbac/pre-health/linkage