WASHINGTON -- The number of federal background checks for firearms sales declined in the U.S. last month, as retailers continue to run out of guns to sell during a buying spree driven by Washington's new focus on gun control.Background checks decreased 10 percent nationally between December and January, with large declines in the Southern states of Alabama, Arkansas, Louisiana, Mississippi, Tennessee and Virginia, as well as in Texas, according to an Associated Press analysis of new FBI data published Tuesday.Firearms sales surged around the country after the December shooting spree in Newtown, Conn. A gunman killed 20 children and six adults at the school.There were more than 2.78 million checks in December. That was a 12-month peak following an upward trend through last fall. The number fell to 2.48 million in January, still a higher figure than any other month than December last year.One retailer said manufacturers and wholesalers can't fill orders right now because demand is so high.Gun sales traditionally dip after the rush of the holiday shopping season, and the decrease this year is the smallest since 1998 when the federal government began tracking federally mandated National Instant Criminal Background Checks. This year's smaller decrease confirms what gun-sellers have reported seeing: There continues to be a higher interest in firearms than in past years, but there have been fewer buyers because gun stores are out of stock."Availability has been an issue. You're just not able to sell as much," said Katie Stulce who owns Champion Firearms Corp. in College Station. "We're probably turning away 60 percent of the people coming in wanting to buy something."The number of background checks does not necessarily represent the number of firearms purchased, but gun manufacturers use these statistics to measure the health of the gun industry in the U.S. Louisiana, Alabama and Mississippi saw the largest declines in background checks from December to January, by nearly one-third.