WASHINGTON (AP) — Sales of new U.S. homes plummeted 9.4 percent in July, the sharpest one-month drop in nearly a year. But the decline followed strong sales in previous months, and sales so far this year are outpacing last year's.

The Commerce Department said Wednesday that new-home sales fell to a seasonally adjusted annual rate of 571,000 in July, down from 630,000 in June. Last month's figure was the weakest since December.

Still, sales in the first seven months of the year are 9.2 percent higher than in the same period last year. More buyers are turning to newly built houses as the supply of existing homes for sale has fallen steadily.

The housing market overall is mostly healthy, but sales have stumbled this summer as a supply crunch has elevated average home prices nationwide. The rising prices have made homes too expensive for some would-be buyers, even as healthy hiring has lowered the unemployment rate to a 16-year low of 4.3 percent.

Builders are ramping up the supply of new homes, providing a crucial outlet. But the number of newly built properties available is still below historical levels. Even so, the supply of new homes for sale ticked up 1.5 percent in July from June to 276,000. That's 16.5 percent higher than a year earlier.

That level is considered enough to last 5.8 months at the current sales pace — near the 6 months that is typical in a healthy market.

By contrast, the number of existing homes for sale plunged 7.1 percent in June from a year earlier. The larger supply of new homes has kept prices from rising as much as in the market for existing houses. A typical new home sold for $313,700 in July — below the $316,200 typical price for all of last year.

Prices for existing homes rose 5.6 percent in May from the previous year, the latest data available, according to the S&P Case-Shiller home price index.