WASHINGTON (AP) — Long-term U.S. mortgage rates slid this week from their highest levels of 2017.

Mortgage buyer Freddie Mac said Thursday that the rate on 30-year, fixed-rate home loans fell to 4.23 percent from 4.30 percent last week. The benchmark rate stood at 3.71 percent a year ago and averaged 3.65 percent in 2016, lowest in records dating to 1971.

The rate on 15-year mortgages tumbled to 3.44 percent from 3.50 percent.

Last week's rates were the highest of 2017.

Mortgage rates rose sharply after the Nov. 8 election. Investors bid rates up because they expect President Trump's plans to cut taxes and increase spending on defense and infrastructure to push economic growth and inflation higher.

The Federal Reserve last week raised short-term rates for only the third time since 2006, a vote of confidence in the health of the U.S. economy.

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 was unchanged this week at 0.5 point. The fee on 15-year loans also remained at 0.5 point.

Rates on adjustable five-year loans tumbled to 3.24 percent from 3.28 percent last week. The fee remained at 0.4 point.