U.S. sales of previously occupied homes fell unexpectedly in December, but for all of 2012, existing-home sales rose to their highest level in five years, an industry group reported Tuesday. The National Association of Realtors (NAR) said sales dropped 1 percent in December to an annual rate of 4.94 million units. Despite the decline, it was the second-highest monthly rate of sales in three years. Last year ended as the best for home resales since 2007, with total sales reaching 4.65 million, up 9.2 percent from 2011. However, sales still are below the 5.5 million that are consistent with a healthy housing market. The U.S. housing market collapsed ahead of the 2007-2009 Great Recession and has not yet fully recovered, but steady job creation and record-low mortgage rates helped the housing sector in 2012, when it likely added to economic growth for the first time since 2005. Still, the market is being limited by the shrinking supply of homes for sale. The inventory of available homes on the market fell to 1.82 million in December, the lowest in 12 years. The low inventories are encouraging multiple bids on homes and helping to support prices, NAR chief economist Lawrence Yun said. Nationally, the median price for a home resale was up 11.5 percent in December from a year earlier. First-time homebuyers, critical to a housing recovery, comprised only 30 percent of sales in December, down slightly from a year ago and well below the 40 percent that is typical in a healthy market.