As borrower delinquencies rose, TransUnion LLC's Credit Risk Index increased 2.3%, to 123.36 in the fourth quarter from the previous quarter.

This was the first increase in the measure since the fourth quarter of 2009 when it peaked, the Chicago company said Tuesday. Despite this uptick, the CRI was down 1.7% year over year.

The CRI measures the risk inherent in the U.S. credit-using population. A higher number means a higher level of credit risk.

Slight rises in delinquency rates in the fourth quarter on credit cards and mortgages contributed to the index's increase, said Charlie Wise, director of research and consulting at TransUnion, in a press release. The increase in the percentage of non-prime consumers with an active bank card may have also contributed.

"As lenders make credit more widely available at the riskier end of the credit spectrum, it is inevitable that the risk of default will increase for the population on average," Wise said in the release.

Increases are generally expected during the last three months of the year due to holiday shopping, TransUnion said.

South Carolina had the highest CRI at 156.13, followed by Nevada at 155.95 and Mississippi at 155.48. North Dakota had the lowest CRI at 77.37.

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