(over past four quarters, seasonally-adjusted housing prices fell 5.9 percent, and housing prices 0.6 percent lower in second quarter of 2011 than in first quarter of 2011; June 2011 housing price index 18.8 percent lower than April 2007 peak; in Iowa, housing prices have decreased 1.61 percent over last five years; national average decline over past five years is 18.78 percent).