NEW YORK (CNNMoney.com) - Flagler County, Florida has retained its status as the fastest growing county in the United States, based on rate of population gains, according to the latest Census Bureau statistics.

During the 12 months ended July 1, 2005, Flagler's population grew 10.1 percent to 76,410. The population is 53 percent more than recorded in the 2000 census.

Lyon County, Nevada, finished second among the nation's 3,141 counties, with a growth rate of 9.6 percent.

Only one of the top-10 fastest-growing counties lies outside the South or West. Kendall, Illinois, near Chicago, came in third at 9.4 percent. Grundy, Illinois, just missed the cut, ranking 11th.

There were three Virginia counties in the top 10: Loudoun, near Washington, D.C., King George and Caroline.

In terms of sheer numbers, Maricopa County, Arizona, which includes Phoenix, added 137,000 residents, the most of any U.S. county.

On the downside, Chattahoochee County in Georgia had the dubious distinction of losing 6.2 percent of its residents, a greater percentage loss than any other county.