The average rate on a 30-year U.S. mortgage rose for the second week in a row, another setback for the U.S. housing market, which is mired in a sales slump as affordability constraints shut out prospective homebuyers.

The long-term rate ticked up to 6.75% from 6.72% last week, mortgage buyer Freddie Mac said Thursday. A year ago, the rate averaged 6.77%.

The average rate has remained relatively close to this year’s high of just above 7% in mid-January.

Borrowing costs on 15-year fixed-rate mortgages, popular with homeowners refinancing their home loans, also rose. The average rate increased to 5.92% from 5.86% last week. A year ago, it was 6.05%, Freddie Mac said. — Associated Press