WASHINGTON (MarketWatch) — U.S. house prices in December were 8.3% higher than a year earlier, the strongest advance since May 2006, CoreLogic said Tuesday. But the data also show the considerable distance to go before the housing market reaches prerecession peaks. The December monthly price gain was 0.4%. CoreLogic said 46 of 50 states registered gains for the year. Arizona has the strongest year-on-year appreciation at 20.2%, though prices are down 39.8% there from the peak.