Without southern Delaware, the state’s population would be stagnating.

Delaware’s population inched closer to one million in 2016, propelled by growth in Sussex County, according to the U.S. Census Bureau’s latest population estimates, released Thursday.

Of the 6,131 new residents in Delaware in 2016 compared to the previous year, 4,629 were in the state’s southernmost county.

Strips of land near Sussex County’s beaches and inland bays account for most of its recent growth, said County Administrator Todd Lawson. Home building there has occurred at a rapid clip, according to permit data, he said.

It is transforming the once-secluded beach destination into a year-round community.

“It’s a good problem to have if you even want to call it a problem, to have more people who want to live in your community,” Lawson said. "Anecdotally, we are seeing a large amount of people who are choosing to come here and retire."

Sussex County’s estimated 2016 population was 220,251, up 2.1 percent from the previous year. It has grown 11.7 percent since the Census Bureau last counted every person in the country in 2010.

Despite Sussex growth, the state’s population from 2015 to 2016 increased just 0.6 percent to 952,065, a slower pace than past years.

New Castle County – still the largest in Delaware by a wide margin – grew by just 208 residents or 0.03 percent between 2015 and 2016 to reach a population of 556,987.

Wilmington, Delaware's largest city, lost 506 people from 2015 to 2016, according to the data.

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Kent County, like its geography, lies in the middle with a growth rate of 0.7 percent during the time span, and a total population of 174,827. The county encourages growth in established municipalities and between the U.S. 13 and Del. 1 corridors, said Rich Vetter, executive director of the Dover, Kent County Metropolitan Planning Organization.

“That’s where we tend to see the growth,” he said. “There’s a lot of preservation areas that are outside of those areas.”

If the state’s roughly 1 percent average annual growth rate since 2010 continues, Delaware will have one million residents by 2021.

The Census Bureau's population estimates are based upon current data on births, deaths, and migration.

Contact Karl Baker at kbaker@delawareonline.com or (302) 324-2329. Follow him on Twitter @kbaker6.