Washington ? Rates on 30-year mortgages dropped to a new low this week, offering Americans a good reason to jump on the home mortgage refinancing bandwagon.

Mortgage giant Freddie Mac, in its weekly nationwide survey of mortgage rates, reported Thursday that the average interest rate on 30-year fixed-rate mortgages fell to 5.98 percent, the lowest level since Freddie Mac began tracking these rates in 1971.

That not only was an improvement over last week’s average rate of 6.01 percent but also represented the sixth time this year that rates on 30-year mortgages hit record lows. This week’s rate barely inched out the prior low of 5.99 percent, which was set at the end of September.

Mortgage rates have been falling amid an uneven economic recovery and a roller coaster stock market that has sent investors to the bond market, helping to push long-term rates down.

“The economy appears to be growing, albeit very slowly,” said Phil Colling, economist with the Mortgage Bankers Association of America.

Low mortgage rates are feeding a boom in mortgage refinancing. Savings or extra cash coming out of refinancing deals is helping to support consumer spending amid uncertain economic times and eroding consumer confidence.

The mortgage bankers association reported Wednesday that mortgage loan applications reached a record level last week.