A new study by Arizona State University suggests the rate of decline in Valley home values may be slowing.

The ASU Repeat Sales Index measures the change in average Phoenix-area home prices compared with the same month the previous year.

The latest report released Monday shows a record 37 percent fall in the index from February 2008 to February 2009. But that is followed by lesser declines - an estimated 36 percent from March 2008 to March 2009 and an estimated 34 percent drop from April 2008 to April 2009.

"In this market, this would be considered good news," said Karl Guntermann, a real estate professor at the W.P. Carey School of Business at ASU. "Before this reversal, we were seeing the index drop another 1 to 2 percent every month."

The index has declined every month for two straight years, eclipsing the previous record of 17 consecutive months of year-over-year drops in the early 1990s.

The median Phoenix-area home price in April was about $117,500, Guntermann calculates, which puts prices back to the level of November 1998.