Freddie Mac says the average rate on a 30-year mortgage fell to 6.63% this week, its lowest level since mid-December.

Borrowing costs on 15-year fixed-rate mortgages, popular with homeowners seeking to refinance their home loan to a lower rate, also eased this week. The average rate fell to 5.79% from 5.94% last week. A year ago, it averaged 6.22%, Freddie Mac said.

Mortgage rates are influenced by several factors, including bond market investors’ expectations for future inflation, global demand for U.S. Treasurys and the Federal Reserve’s interest rate policy decisions.

The recent decline in mortgage rates echoes moves in the 10-year Treasury yield, which lenders use as a guide for pricing home loans.