WASHINGTON (AP) — Long-term U.S. mortgage rates declined this week after two straight weeks of increases. The benchmark 30-year rate slipped back below the significant 4 percent level.

Mortgage buyer Freddie Mac said Thursday that the rate on 30-year, fixed-rate mortgages fell to an average 3.96 percent from 4.03 percent last week. It stood at 3.45 percent a year ago and averaged a record low 3.65 percent in 2016.

The rate on 15-year, fixed-rate home loans, popular with homeowners who are refinancing their mortgages, eased to 3.23 percent from 3.29 percent last week.

Mortgage rates still remain historically low even though the Federal Reserve has begun to ratchet up short-term interest rates.

To calculate average mortgage rates, Freddie Mac surveys lenders across the country between Monday and Wednesday 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 rose to 0.6 point from 0.5 point last week. The fee on 15-year loans was unchanged at 0.5 point.

Rates on adjustable five-year loans dipped to 3.21 percent from 3.28 percent last week. The fee held steady at 0.5 point.