Home prices in metro Atlanta rose 18 percent in December compared with a year ago, according to the latest S&P Case-Shiller Home Price Index figures released Tuesday.

Atlanta had the fourth highest appreciation rate among the 20 cities studied. Nationally, the average increase was 11.3 percent.

This is the 13th consecutive month of double-digit home price increases in metro Atlanta. Price increases are expected to stay in the double digits throughout the year, as more people enter the market and inventory stays low.