Central Oregon’s population got a little older in the last two years, new data from the U.S. Census Bureau show.

All three counties saw fairly substantial gains in the number of residents aged 65 and older between 2010 and 2012, along with a stagnant to slightly declining number of people under the age of 50.

The figures were released today as part of the Census Bureau’s annual population estimates for communities across the country.

They show Deschutes County’s median age was 41.5 as of July 1, up from 40.3 on July 1, 2010.

Crook County’s median age rose from 45.8 to 47.4 over the same time span, and Jefferson County’s from 39.7 to 40.1.

The number of Deschutes County residents age 65 and older rose by 3,284 over that time. Crook County’s over-65 population rose by 388, and Jefferson County’s over-65 population rose by 230.

Central Oregon is known for attracting tourists and retirees, said Risa Proehl, population estimates program manager with the Portland State University Population Research Center. An influx of retirees could explain the age increase in Deschutes County, Proehl told The Bulletin in an email.

Data released earlier this year by the Census Bureau showed more than 3,200 people moved into Deschutes County from other parts of the country between 2010 and 2012.

Population gains in the county are “mostly attributed to an to an increase in the number of people ages 65 and over,” Proehl wrote. “Seniors are likely moving to Deschutes County because of outdoor recreational opportunities, the climate, and the sense of community that many areas in the county possess, while still being large enough to offer services they desire, such as medical, retail and entertainment.”

But it’s likely a different story in Crook and Jefferson counties, which saw more people move out of the area than in over the same time span.

In July , Crook County had 331 fewer residents aged 25 to 59 than in July 2010. Jefferson County had 123 fewer residents in that age range.

Some of those people may have left for job opportunities in other communities, including Deschutes County and especially in Bend, said Kreg Lindberg, an Oregon State University-Cascades Campus associate professor who researches population and migration trends.

All three Central Oregon counties have unemployment rates higher than the state average. But Deschutes County’s jobless rate was 10.1 percent in April, compared with 11.1 percent in Jefferson County and 12.8 percent in Crook County.

“It wouldn’t surprise me if some of those younger people were coming (to the Bend area), not only because of the natural amenities but because of greater economic opportunities,” Lindberg said.

Still, Deschutes County had just 150 more people in the

25-59 age range last year than in 2010. The number of county residents under the age of 5 dropped by 372, meanwhile, and the total population under age 18 fell by just six people.

Jefferson County had just three fewer people under the age of 5 in that two-year time span, and 68 fewer people under the age of 18.

Crook County had 125 fewer people under the age of 5 and 346 fewer people under the age of 18.