Real estate data analytics firm, Zillow, reported that more than 28 percent of US homeowners are currently underwater on their mortgages; data by CoreLogic in early March had previously measured this rate at 23 percent.

According to Zillow, its home value index for the first-quarter came in at $169,600. HousingWire reported that this was the steepest first-quarter decline since 2008, an 8.2 percent loss compared to first-quarter 2010.

“Home value declines are currently equal to those we experienced during the darkest days of the housing recession,” Zillow Chief Economist Stan Humphries said. “With accelerating declines during the first quarter, it is unreasonable to expect home values to return to stability by the end of 2011. We did expect substantial payback from the homebuyer tax credits, which buoyed the housing market last year, but underlying demand post-tax credit, as well as rising foreclosures and high negative equity rates, make it almost certain that we won’t see a bottom in home values until 2012 or later.”

Additionally, Zillow found that foreclosure rates for March rose, with a rate of one out of every 1,000 US homes being lost to foreclosure.

However, Zillow tracked home-value gains in Fort Myers, Fla., Champaign-Urbana, Ill., and Honolulu, Hawaii.