NEW YORK - The housing slump isn't over. Tax credits and historically low mortgage rates have failed to lift home prices so far this year. Prices fell 0.5 percent in March from February, according to the Standard & Poor's/Case-Shiller 20-city index released Tuesday .

The month-to-month drop from February to March marked the sixth straight decline. Prices in 13 of the cities fell.

Prices remain nearly 31 percent below their July 2006 peak. But they have risen nearly 3 percent from their April 2009 bottom.