The fixed rate on the 30-year mortgage set another record low this week, moving down a notch to 4.57 percent, from last week’s 4.58 percent, according to Freddie Mac.

A year ago, the 30-year rate was at 5.2 percent.

The 15-year fixed-rate mortgage nudged up to 4.07 percent, from last week’s record low of 4.04 percent. Last year at this time, the 15-year rate stood at 4.69 percent.

The 5-year Treasury-indexed hybrid, adjustable-rate mortgage also hit a new low, down to 3.75 percent in the latest week, down from 3.79 percent a week earlier – and from 4.82 percent a year ago.

“With mortgage rates falling to historic lows, refinance activity has been strong over the past three months,” said Frank Nothaft, Freddie Mac’s chief economist

The Mortgage Bankers Association reported yesterday that the refinance share of mortgage activity increased last week to 78.7 percent of total applications from 76.8 percent the previous week, which is the highest refinance share observed in the survey since April 2009.