Home values in the United States posted their largest quarterly decline since the first quarter of 2009, falling 2.6 percent as the temporary stimulus of the home buyer tax credits wore off, according to Zillow’s fourth quarter Real Estate Market Reports. The Zillow Home Value Index declined 5.9 percent year-over-year in the fourth quarter to $175,200. Home values have fallen 27 percent since they peaked in June, 2006. Zillow says accelerating home value declines, as well as a slowdown in the nation’s foreclosure rate following the late-2010 robo-signing controversy, contributed to an increase in negative equity. At the end of the fourth quarter, 27 percent of single-family homeowners with mortgages owed more on their mortgage than their homes were worth, up from 23.2 percent in the third quarter.