WASHINGTON (AP) — The costs of borrowing to buy a home increased slightly this week, but U.S. mortgage rates are still near relative lows.

Mortgage buyer Freddie Mac says the average rate on 30-year, fixed-rate mortgages rose to 3.94 percent from 3.88 percent last week. At this time last year, the benchmark rate was 3.47 percent. The historic average was roughly 6 percent.

Long-term home loan rates tend to track the yield on 10-year U.S. Treasury notes. The interest charged on 10-year Treasury notes has risen since early September.

The rate on 15-year, fixed-rate mortgages, popular with homeowners who are refinancing, rose to 3.25 percent from 3.19 percent last week. A year ago, the 15-year rate was 2.78 percent.