He said, "The lion's share of the defaults occur in the unrated market, and they have for many years".
Their official Education Department-published default rates, which look at the share of borrowers who default within three fiscal years of their loans first coming due, were much lower, sometimes by half as much.
These markets were the most overbuilt, have experienced the largest price drops, and are home to a large share of foreclosure and default activity.
It would also provide information about the colleges' retention and graduation rates and the share of graduates who default on their student loans.
Navient has the fewest share of borrowers in default, Education Department data show.
The company has consistently ranked ahead of its three major competitors when it comes to the share of borrowers in default.
By insisting that all new sovereign bonds issued after 2013 carry a clause making investors liable to share losses in case of default, Berlin has made it even harder for Greece to return to the capital markets, starting in 2014.
Last summer, Duncan took credit for a small drop in the share of borrowers who defaulted early on their federal loans.
Students at for-profit colleges are responsible for an outsized share of student loan defaults: although about 12percentt of college students nationwide attend for-profit schools, the sector is responsible for more than 45percentt of federal loan defaults.
