The average rate on a 30-year mortgage in the U.S. rose above 6.8% this week, returning to where it was just three weeks ago.

The rate increased to 6.81% from 6.76% last week, mortgage buyer Freddie Mac said Thursday. A year ago, the rate averaged 7.02%.

Borrowing costs on 15-year fixed-rate mortgages, popular with homeowners refinancing their home loans, also rose. The average rate ticked up to 5.92% from 5.89% last week. It’s down from 6.28% a year ago, Freddie Mac said.

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