FARGO (AP) - Eleven North Dakota counties had population gains in 2005, though most of the state's 53 counties continued to lose people, the North Dakota State Data Center says.

The county population gains combined added 369 people to North Dakota's population last year. It was the first year of an increase since a slide began in 2000.

"Although our statewide population growth in 2005 is modest, what is important is the upward trend in county growth," said Richard Rathge, the data center's director and North Dakota's demographer. "Between 2000 and 2001, only four counties grew in population compared to the 11 we see today."

North Dakota's population gains in recent years have been concentrated in Fargo and West Fargo, Bismarck and Mandan, and the reservation counties of Sioux and Rolette. Those two counties gained 44 and 48 people respectively, both largely due to high birth rates.

Burleigh County, which includes Bismarck, posted the biggest percentage gain at 1.7 percent, adding 1,255 people. Cass County had the biggest numeric gain, 1,436 people, an increase of 1.1 percent. Morton County, home to Mandan, gained 206 people, or 0.8 percent.

Grand Forks County lost 74 people and Ward County, which includes Minot, lost 662, a drop of 1.2 percent, according to the estimates.

The Census Bureau does a population count every 10 years but releases annual estimates based on births, deaths and migration patterns.

Other North Dakota counties showing modest growth include Benson County, up one person; Eddy County, up 9; McKenzie County, 87; Sargent County, 29; and Williams County, which includes Williston, adding 38 people.

North Dakota's population continues to be centralized, with 55.3 percent of residents living in five counties: Cass, Burleigh, Grand Forks, Ward and Morton.

Benson County's estimated population grew by one person last year, to 6,999. The number of residents is up 35 from the 2000 census count.

"There's been a couple births and there's been a couple deaths," said Janine Gigstad, manager of White Drug in Maddock. "We lose some and we gain some."