The number of U.S. households that are falling behind on their mortgages has hit a new high.

The Credit Agency Transunion reports that 6.25 percent of U.S. mortagages are 60 days or more past due.

A year ago that number was just under 4 percent.

Transunion says there's a silver lining in the numbers. The rate of troubled mortgages increased at a slower pace over the summer.

However, the figure is not expected to start going down until next year.

The statistics, which are culled from TransUnion's database of 27 million consumer records, show that mortgage delinquencies remain highest in the four states where the crisis has hit the worst.

• In Nevada, the rate reached 14.5 percent, up from 7.7 percent a year ago.
• In Florida, the rate was 13.3 percent, up from 7.8 percent last year.
• In Arizona, the rate hit 10.4 percent, up from 5.5 percent in 2008.
• In California, the rate jumped to 10.2 percent, from 5.8 percent last year.
• North Dakota remained the state where mortgage holders most often paid on time, with just 1.7 percent delinquency, up from 1.4 percent last year.

The average mortgage debt per borrower nationwide edged up to $193,121 in the third quarter, from $192,287 last year.

The District of Columbia had the highest average mortgage debt per borrower at $359,788. The lowest average mortgage debt per borrower was in West Virginia at $97,265.