Average U.S. mortgage rates started the year by dipping to new lows, with the benchmark 30-year rate marking its lowest level since May 2013.

The mortgage giant Freddie Mac says the nationwide average for a 30-year fixed rate mortgage fell to 3.73 percent this week from 3.87 percent last week.

The average for a 15-year mortgage slid to 3.05 percent from 3.15 percent last week.

A year ago, the 30-year mortgage stood at 4.51 percent and the 15-year mortgage at 3.56 percent. Mortgage rates have remained low even though the Federal Reserve in October ended its monthly bond purchases, which were meant to keep long-term rates low.

The decline in mortgage rates also has come as bond yields have hit record low levels. Mortgage rates often follow the yield on the 10-year Treasury note, which has fallen below 2 percent. Bond yields rise as prices fall.

Bond prices were an unexpected strong spot for the financial markets last year.

The 10-year note traded at 1.97 percent Wednesday, down from 2.17 percent a week earlier. It recovered to trade at 2 percent Thursday morning.

To calculate average mortgage rates, Freddie Mac surveys lenders across the country at the beginning of each week. The average doesn’t include extra fees, known as points, which most borrowers must pay to get the lowest rates. One point equals 1 percent of the loan amount.

The average fee for a 30-year mortgage was 0.6 point, unchanged from last week. The fee for a 15-year mortgage declined to 0.5 point from 0.6 point.

The average rate on a five-year adjustable-rate mortgage fell to 2.98 percent from 3.01 percent. The fee was unchanged at 0.5 point.

For a one-year ARM, the average rate slipped to 2.39 percent from 2.40 percent. The fee held at 0.4 point.

(AP)