The number of young borrowers who have fallen behind on their student loan payments has soared over the past four years, the Federal Reserve Bank of New York said in a recent report, according to the Wall Street Journal.

According to the report, 35 percent of people under age 30 who have student loans were at least 90 days late on their payments at the end of last year, up from 26 percent in 2008 and 21 percent at the end of 2004.

All told, 43 percent of 25-year-olds had student debt in the fourth quarter of 2012, up from about 33 percent in the fourth quarter of 2008.

The new figures, which exclude borrowers who are still in school or aren’t yet required to make payments, show that young Americans are having a tougher time repaying college loans as debt loads increase and job prospects remain shaky.

The amount of U.S. student-loan debt increased 11 percent last year to $966 billion and is up 51 percent since 2008, according to the report.

While 40 percent of student-loan borrowers owe less than $10,000, a growing number have higher loan balances.

Nearly 47 percent of borrowers owe between $10,000 and $50,000, up from 38 percent in the fourth quarter of 2005.

The share of borrowers with balances of $100,000 or more has also jumped, to 3.7 percent from 1.7 percent during this period.

Read More: