Something for all those just-admitted high-school seniors to think about. Far more students have difficulty repaying their student loans than previously thought. Statistics typically track students who default on their loans, but a recent survey by the Institute for Higher Education Policy found that for every student who defaults, two more are delinquent on monthly payments. In all, one in four students have trouble making full monthly payments. The number of college students graduating with debt has gone from less than half in 1993 to two-thirds in 2008, and the average debt has risen sharply, to $23,000 in 2008 from $18,650 four years earlier. But part of the problem is that loan-guaranty agencies haven't been telling students they can put loans in forbearance or deferral, which keeps loans from going into default. "Many borrowers end up becoming delinquent or defaulting because they don't know all of the options available to them," said Debra Chromy, vice president of government services at nonprofit guaranty agency American Student Assistance.