The 30-year fixed-rate mortgage plunged 22 basis points this week, the largest one-week drop in 10 years, Freddie Mac reports in its weekly mortgage survey.

“The Federal Reserve’s concern about the prospects for slowing economic growth caused investor jitters to drive down mortgage rates by the largest amount in over ten years,” says Sam Khater, Freddie Mac’s chief economist. “Despite negative outlooks by some, the economy continues to churn out jobs, which is great for housing demand. We have recently seen home sales start to recover and with this week’s rate drop, we expect a continued rise in purchase demand.”

Freddie Mac reports the following national averages with mortgage rates for the week ending March 28:

30-year fixed-rate mortgages: averaged 4.06 percent, with an average 0.5 point, falling from last week’s 4.28 percent average. Last year at this time, 30-year rates averaged 4.40 percent.

15-year fixed-rate mortgages: averaged 3.57 percent, with an average 0.4 point, dropping from last week’s 3.71 percent average. A year ago, 15-year rates averaged 3.90 percent.

5-year hybrid adjustable-rate mortgages: averaged 3.75 percent, with an average 0.3 point, falling from last week’s 3.84 percent average. A year ago, 5-year ARMs averaged 3.66 percent.

Source: Freddie Mac