Also, the number of rented homes grew much faster than owner-occupied homes -- by 26.4 percent, compared with 5.3 percent.
The U.S. Census Bureau on Thursday released demographic data for population and housing in South Carolina, which was collected as part of the 2010 census.
Figures show that senior populations swelled across Aiken, Allendale, Bamberg, Barnwell, Edgefield, Hampton, McCormick and Saluda counties, especially among people who are close to retirement age.
In total, the counties gained 18,471 people ages 55 to 69 in those 10 years. The region's entire population is 287,309.
At the same time, the counties lost 3,925 children ages 5 to 14. It lost 7,787 people ages 30 to 44.
In McCormick County, where the median age now stands at 50, the population of school-age children dropped 30.7 percent, from 1,096 to 750.
J. David Jameson, the president and CEO of the Greater Aiken Chamber of Commerce, said one reason Aiken attracts senior citizens is that local retirement communities have actively courted them.
Not that it's a hard sell. Aiken has been named as one of the best places to retire by several national publications.
"Aiken attracts a very high-end retiree, seniors who have been managers and owners of companies," Jameson said. "They come for the golf, for horses, the climate, the quality of life and the cost of living."
Glenn Parker, the director of Aiken's Parks and Recreation Department, said that during the 1980s demand for children's recreation programs exploded in Aiken. Today, that has leveled off, and demand for senior programs is increasing.
"Our 'silver sneakers' program, which is a fitness program for seniors, is very popular. It's been growing by 10 to 15 percent every month," Parker said.
The program at one time used a 30-passenger bus for senior excursions to places such as Charleston, S.C. Today, it hires 50-passenger charter buses.
Aiken even recently formed a senior commission to look into issues particular to older residents.
A less-welcome trend for the decade shows that the number of rented homes grew five times faster than the number of owner-occupied homes.
The region added 14,693 homes during the 10-year period, but only 4,135 of those are being lived in by owners. An additional 6,264 are rentals, and 4,294 are vacant.
In Edgefield County, for example, rentals grew by 38.8 percent.
Judy Pendarvis, an agent for Edgefield Southern Realty, said the foreclosure crisis is responsible. Half of her real estate business is now dealing in foreclosures.
"As people lose their homes, they're ending up in rentals," Pendarvis said.
Edgefield County has virtually no apartments, she said, but new rentals come on the market when people move away and can't sell their houses.
The rental market is strong, even though home sales are down, she said. For those who can afford to buy a home, there are some great deals.
"I've never had a better year in real estate. Your money can go a long way right now," she said.