More US college students are graduating with loans to pay for school and the amount of their debt has increased over the years, according to a new report released Wednesday.

Seven in 10 college seniors who graduated in 2012 had student loan debt, with an average of 29,400 US dollars for those with loans. The national share of seniors graduating with loans rose from 68 percent in 2008 to 71 percent in 2012, while their debt at graduation increased by an average of six percent per year, based on data from the "Student Debt and the Class of 2012" study by the Institute for College Access & Success.

Even though the financial crisis caused a substantial decline in private education lending while these borrowers were in school, about one-fifth of their debt is comprised of private loans, which are typically more costly and provide fewer consumer protections and repayment options than safer federal loans, the 28-page-long report says.

State averages for debt at graduation ranged widely in 2012, from 18,000 dollars to 33,650 dollars, and graduating seniors' likelihood of having debt ranged from 41 percent to 78 percent. In five states, average debt was more than 30,000 dollars. High-debt states remain concentrated in the Northeast and Midwest, with low- debt states mainly in the West and South, according to the report.

The state and college debt figures in this report reflect only graduates of public and private nonprofit four-year colleges, because so few for-profit colleges choose to report the necessary data, the report says.

According to its website, the Institute for College Access & Success is an independent, nonprofit organization that works to make higher education more available and affordable for people of all backgrounds.