Sales of new single-family homes rose sharply in July but median prices fell 2.5 percent, the U.S. government reported Thursday, providing mixed signals about the strength of the nascent housing-market recovery. The Commerce Department said new-home sales rose 3.6 percent last month to an annual rate of 372,000 units, matching a two-year high recorded in April. Economists had expected a modest rise to a 365,000-unit pace. In the past 12 months, new-home sales have risen 25 percent. Still, the increase is from a historically low level, as sales are well below the annual pace of 700,000 that economists consider healthy. One trend limiting sales is that there are not many newly built homes available. New homes for sale declined in July to 142,000, the lowest on records dating back to 1963. The housing market has showed some signs of sustainable growth in the past few months, and homebuilding is expected to add to overall economic growth this year for the first time since 2005.