College seniors who graduated with education loans in 2011 owed $26,600 on average, up 5.3 percent from a year earlier, as students shoulder more of the cost of their undergraduate degrees.

About two-thirds of all students took on debt, unchanged from the previous period, according to a report released Thursday by The Institute for College Access & Success, an Oakland, California-based nonprofit group.

Students in New Hampshire had the highest level of debt on average at $32,440, while students in Utah had the lowest, at $17,227, according to the study. With college costs climbing faster than the rate of inflation over the past four decades, students have taken out more loans, swelling outstanding education debt to $1 trillion, more than what Americans owe on their credit cards.

More than one in 10 borrowers defaulted on their federal student loans in the first three years they are required to make payments, the U.S. Education Department said last month. The government report covers the period through Sept. 30, 2011.

The 2011 figures from the College Access group are based on cumulative student debt from federal and private loans at public and nonprofit four-year colleges. The study was compiled from federal data and a survey of 1,057 schools that award bachelor’s degrees by Peterson’s, a company that provides information about college.