Mortgage rates sank to their lowest levels of the year this week but remain well above where they were six months ago.

According to the latest data released Thursday by Freddie Mac, the 30-year fixed-rate average dropped to 3.95 percent with an average 0.5 point. Points are fees paid to a lender equal to 1 percent of the loan amount. It was 4.02 percent a week ago and 3.64 percent a year ago. It is only the second time this year the 30-year fixed rate has dipped below 4 percent.

The 15-year fixed-rate average fell to 3.19 percent with an average 0.5 point. It was 3.27 percent a week ago and 2.89 percent a year ago. The five-year adjustable rate average tumbled to 3.07 percent with an average 0.4 point. It was 3.13 percent a week ago and 2.87 percent a year ago.

Last week’s sharp drop in Treasury yields sent mortgage rates to their lowest levels since mid-November. The yield on the 10-year bond declined to 2.22 percent on May 17, falling 11 basis points in one day. A basis point is 0.01 percentage point.

It has recovered slightly, but remains well below its peak earlier this month of 2.42 percent. Because the movement of long-term bond yields tends to be one of the best indicators of where mortgage rates are headed, home loan rates also ebbed.

Bankrate.com, which puts out a weekly mortgage rate trend index, found that close to two-thirds of the experts it surveyed say rates will remain relatively stable in the coming week. Almost a third say they will rise.