A Primary Mortgage Market Survey by the McLean, Virginia-based mortgage finance company Freddie Mac has revealed that US home loan rates have almost hit rock-bottom, with only diminutive further decreases possible hereafter.

Noting that the 30-year fixed-rate mortgage rate has plunged to its record lowest level, since the Freddie Mac weekly survey began in 1971, the company's interim CEO John Koskinen said that if mortgage rates go down any further than the current ones, the fall will only be "incremental."

Koskinen said the yearly rate charged on the most common home loans has plunged considerably in the last few months, particularly as officials have tried to loosen the credit controls.

Figuratively speaking, the March 26 week-ending survey shows the 30-year fixed-rate mortgage averaged 4.85, going down from the earlier week average of 4.98 percent. A year back, the 30-year fixed-rate mortgage averaged 5.85 percent.

On July last year, the rates for 30-year fixed-rate mortgages reached the peak at 6.63 percent. With this week's 30-year fixed-rate mortgage, the difference in interest rate is almost 2 percentage points, which for a loan of $200,000 adds up to a savings of nearly $225 in monthly mortgage payments.