U.S. home prices jumped 3.8 percent in the 12 months ending in July - with Arizona among states leading the way, according to CoreLogic, a private real-estate data provider.

The year-over-year U.S. increase was the biggest in six years, further evidence that the housing market is steadily recovering.

The states with the biggest gains according to CoreLogic over the past 12 months were Arizona, Idaho, Utah, South Dakota and Colorado. In Arizona, prices have risen 16.6 percent since July 2011. Idaho has posted a 10 percent gain in that time.

Nationwide, home prices also rose 1.3 percent in July from June, CoreLogic said Tuesday. That's the fifth straight increase in both the monthly and year-over-year price indexes.

The index is the third national measure to show steady increases. The Standard & Poor's/Case-Shiller index posted its first annual increase in nearly two years last week. And a federal government housing agency has also reported annual increases.

Not all states are seeing increases, CoreLogic said. In Delaware, prices dropped 4.8 percent in the 12-month period. Prices fell 4.6 percent in Alabama in that stretch.

The housing market has been slowly recovering this year. Sales of new and previously occupied homes are up. Builders are more confident and starting work on more homes. And mortgage rates are near their lowest levels of the past six decades.

Prices are also rising because the supply of available homes remains tight.

Still, the housing market's recovery is just beginning. Prices remain 27 percent below their peak in April 2006, CoreLogic said.

The recent improvements have been widespread. Out of 100 large cities tracked by CoreLogic, only 23 posted year-over-year declines in July. That's four fewer than in June.