I agree; maybe this graph is a little better:

http://www.npr.org/news/graphics/2011/05/gr-avg-student-debt...

(from http://www.npr.org/2011/05/16/136214779/college-student-debt... )

EDIT: Or this maybe: http://www.worldwidehippies.com/2011/08/29/tax-breaks-for-ri...

(just doing an image search for student debt history)