WASHINGTON >> The average U.S. rate on the 30-year fixed mortgage stayed this week at the lowest level on record. Cheap mortgages have helped drive a modest housing recovery and could give the broader economy a jolt at a time when the job market is weak.

Mortgage buyer Freddie Mac says the average on the 30-year loan was 3.66 percent. That’s unchanged from last week and the lowest since long-term mortgages began in the 1950s.

The average rate on the 15-year mortgage, a popular refinancing option, slipped to 2.94 percent. That’s down from 2.95 percent last week and matches the record-low 2.94 percent reached three weeks ago.

The rate on the 30-year loan has been below 4 percent since December.