VALLEY — According to new data released by the U.S. Census Bureau, all but nine Colorado counties grew in population from 2016 to 2017. El Paso County had the largest county increase in the state of 12,526 followed by Weld with 10,390 more residents, Denver increased by 9,844, Douglas saw 7,577 more and Arapahoe gained in population by 6,103. 

"This marks a significant change from 2011 when 36 counties experienced population declines," states a Colorado Department of Local Affairs press release from March 23.

Population estimates are calculated on July 1 each year and show that Denver is the largest county in the state at 704,621 people and El Paso is second with 699,232.

At 3.4 percent Saguache County had the seventh highest growth rate in the state and the largest in the San Luis Valley. The population surged from 6,407 in 2016 to 6,626 in 2017. According to DOLA Chief Administrative Office Natriece Bryant, part of the increase is due to a natural change of 19 residents—the difference between births and deaths—yet the majority is due to a net migration of 200 new residents.

At the 2010 census only 6,108 people resided in the county. Just four years ago the population was estimated to be 6,186.

Alamosa County led the Valley in natural change with an increase of 86 residents and yet the county had only had net migration of nine. The estimated population for 2017 is 16,551.

Conejos County's population grew from 8,072 to 8, 184 while Costilla County went up from 3,705 to 3,776. Mineral County, the smallest the Valley, had a minor increase from 755 to 766 residents.

The fastest growing county in the state was Crowley at 10.6 percent, making it second fastest in the nation. According to DOLA, the growth in Crowley was primarily due to moving prisoners from the Kit Carson Correctional Center, which closed in July of 2016, to the Corrections Corporation of American facility in Crowley and Bent Counties. The closure meant that Kit Carson County experienced the largest decline of population in the state and the percentage loss ranked second largest in the U.S. Kit Carson lost 470 residents at a rate of -6.2 percent.

Also experiencing a loss is Rio Grande County, the only SLV county to dip in population. The county had the fifth highest decline at 37 people and therefore the fifth slowest growth by -0.3 percent. Rio Grande County had a natural change of nine, however, 46 residents moved out of the area and turned the 2017 estimated population into 11,301 people.