Renewed economic worries had mortgage rates falling sharply, with the benchmark conforming 30-year fixed mortgage rate now 4.54 percent, according to Bankrate.com's weekly national survey. The average 30-year fixed mortgage has an average of 0.39 discount and origination points.

The average 15-year fixed mortgage dropped to a new low of 3.68 percent while the larger jumbo 30-year fixed rate retreated to 5.06 percent. Adjustable rate mortgages moved lower also, with the average 5-year ARM sliding to 3.23 percent and the 7-year ARM falling to 3.52 percent.

With the increase in the debt ceiling taken care of, a barrage of poor economic data means we're back to worrying about the economy. These economic worries and increased odds of a double-dip recession had investors flocking into the safety of U.S. Treasury securities - their safe-haven status assured - which fueled the decline in mortgage rates. Fixed mortgage rates are closely related to yields on long-term government bonds.

The last time mortgage rates were above 6 percent was Nov. 2008. At the time, the average 30-year fixed rate was 6.33 percent, meaning a $200,000 loan would have carried a monthly payment of $1,241.86. With the average rate now 4.54 percent, the monthly payment for the same size loan would be $1,018.13, a difference of $223 per month for anyone refinancing now.

SURVEY RESULTS

30-year fixed: 4.54% - down from 4.74% last week (avg. points: 0.39)

15-year fixed: 3.68% - down from 3.83% last week (avg. points: 0.31)

5/1 ARM: 3.23% - down from 3.34% last week (avg. points: 0.38)

Bankrate's national weekly mortgage survey is conducted each Wednesday from data provided by the top 10 banks and thrifts in the top 10 markets.