(Bloomberg Business) — The latest estimates from the U.S. Census Bureau are in, and the fastest-growing city in the U.S. is not an oil boomtown or a magnet for new immigrants, but a senior living community outside Orlando, Fla., with a reputation for attracting active retirees.

The Villages, a sprawling senior community of 114,000 residents, increased 5.4 percent in the year ended July 2014, making it the country's fastest-growing metro for the second straight year. That's triple the growth rate for the state of Florida and far faster than Myrtle Beach, S.C., the second fastest-growing U.S. city, which expanded 3.2 percent.

The explanation is partly semantic. The Census considers the Villages a metropolitan area, based on the area's core density. Some smaller areas, known as micros, grew at faster rates than the Villages, with Williston, N.D., topping the list at 8.7 percent. The Villages is lumped in with such cities as Houston and Dallas, which saw the largest increases in absolute terms but grew more slowly on a percentage basis.