WASHINGTON (AP) — U.S. long-term mortgage rates rose this week for the fourth straight week, though they remain historically low as a spur to home sales in the spring buying season.

Mortgage buyer Freddie Mac says the average rate on the 30-year, fixed-rate mortgage increased to 4.20% from 4.17% last week. By contrast, a year ago the benchmark rate stood at 4.58%.

The average rate for 15-year, fixed-rate home loans rose this week to 3.64% from 3.62% last week.

After peaking at nearly 5% in November, long-term rates started trending downward, helping to boost home sales after a rocky 2018.