WASHINGTON (AP) — U.S. mortgage rates turned down this week, lowering the cost of purchasing a home and supporting the housing market.

Mortgage giant Freddie Mac said Thursday that the average rate for a 30-year fixed mortgage fell to 3.66% this week from 3.75% last week. The average 15-year rate declined to 3.15% from 3.2%.

Rates have fallen sharply in the past year. The National Association of Realtors said Thursday that home sales in October rose 4.6% from a year ago. The construction of new homes and apartments jumped nearly 4% in October.

The 30-year rate has dropped from 3.81% last year, while the 15-year rate was nearly 4.25% a year ago.

Freddie Mac surveys lenders across the country between Monday and Wednesday each week to compile its mortgage rate figures.