WASHINGTON (AP) — Average long-term U.S. mortgage rates fell for the fifth straight week amid volatility in world financial markets.

Mortgage buyer Freddie Mac says the average rate on a 30-year fixed-rate mortgage slid to 3.72 percent this week, down from 3.79 percent last week and the lowest since it averaged 3.68 percent in April 2015.

The average rate on a 15-year fixed-rate mortgage slid to 3.01 percent from 3.07 percent last week.

Mortgage rates have continued to fall despite the Federal Reserve's decision in December to raise the short-term rate it controls for the first time since 2006.

Global markets have been rattled this year by signs of a global slowdown and big drops in the price of commodities, including oil. Investors have sought refuge in U.S. Treasurys, pushing down long-term U.S. rates.

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 unchanged at 0.6 point. The fee for a 15-year loan was also unchanged at 0.5 point.

The average rate on five-year adjustable-rate mortgages fell to 2.85 percent this week from 2.90 percent last week; the fee slid to 0.4 point from 0.5 point last week.