The data is extensive and eye-opening. One thing that jumped out at us right away was the difference in student loan “repayment rates” by type of college. At public colleges, 54% of borrowers were paying down the principal on their loans, compared to 56% of those from private non-profit colleges. But at for-profit colleges, only 36% were paying down their student loans – which means that almost two-thirds of them couldn’t. At the University of Phoenix alone, that amounts to almost $2.8 billion in federal student loan debt that isn’t being paid down.