Sonoma County home prices jumped 16.6 percent in December from a year earlier, according to a real estate information service that measures repeat home sales.

The price increase included foreclosures, short sales and equity sales of both houses and condominiums, according to CoreLogic’s Home Price Index. When distressed sales were excluded, county home prices rose 11.4 percent on a year-over-year basis.

The index takes a different approach at gauging home values than simply measuring the change in median prices. By measuring repeat sales over time, CoreLogic tries to factor out the effect of sales volume shifting between housing segments — for example, when more starter homes or distressed properties are sold in a given month.

Using such repeat sales, CoreLogic reported that U.S. home prices rose 8.3 percent on a year-over-years basis in December. It was the biggest national gain since May 2006, near the height of the housing boom.

Excluding distressed sales, prices increased 7.5 percent.

For California, prices appreciated 12.6 percent, or 12.8 percent when distressed sales were excluded. Only Arizona, Nevada and Idaho registered bigger gains.

“We are heading into 2013 with home prices on the rebound,” said Anand Nallathambi, president and CEO of CoreLogic. “The upward trend in home prices in 2012 was broad based with 46 of 50 states registering gains for the year. All signals point to a continued improvement in the fundamentals underpinning the U.S. housing market recovery.”

December marked the 10th consecutive month of year-over-year price increases for the nation.

CoreLogic’s report suggests the same trend previously reported by other analysts and groups for the county, the Bay Area and California. Those groups all reported December median prices increased more than 20 percent from December 2011.

For example, the county’s median price for a single-family home rose in December to $389,750, according to the Press Democrat’s monthly housing report. That represented an increase of 23.7 percent from a year earlier.