Low mortgage rates may not be enough to stimulate property purchases, according to the latest data from the Mortgage Bankers Association.

The average interest rate for 30-year fixed mortgages fell from 4.96 to 4.83 percent during the week of May 14. For 15-year fixed mortgages, the average interest rate decreased from 4.32 to 4.19 percent, according to the report.

Refinance application rose by almost 15 percent in response to these mortgage rates. The MBA’s Purchase Index, however, fell at an unadjusted rate of 27 percent from the previous week, bringing it to its lowest level since May 1997. This is also 24.1 percent lower than the level witnessed a year earlier.

“The data continue to suggest that the tax credit pulled sales into April at the expense of the remainder of the spring buying season,” Michael Fratantoni, vice president of research and economics for the MBA, said. “In fact, this drop occurred even as rates on 30-year fixed-rate mortgages continued to fall, and at 4.83 percent are at their lowest level since November 2009.”

Consumers had through April 30 to sign on a deal for the federal homebuyer tax credit. Those who did this must close on their purchase by the end of June.