Greater Des Moines house prices, including those for distressed properties, increased by 2.8 percent in May from a year ago. On a month-over-month basis, home prices, including distressed sales, increased by 0.9 percent in May from April, real estate analytics firm CoreLogic Inc. said today. Nationally, prices increased 12.2 percent for the year. Distressed properties are bank-owned or priced at less than their mortgage balance.