Kristi Tanner

Detroit Free Press Staff Writer

Genesee County ranked 8th in the U.S. for numeric population decline, a loss of 2,085 people last year.

Saginaw County ranked 12th in the U.S. for numeric population decline, a loss of 1,835 people last year.

After eight years of leading the nation in population loss, Wayne County ranked second last year behind Cook County, Illinois, according to Census data released today.

Wayne County lost 6,673 people between July 1, 2014 and July 1, 2015 — a 0.4% drop to 1.76 million residents. Cook County, home of Chicago, lost 10,488 residents, a 0.2% decline over the same time period. The last time Cook Cou nty declined in population was 2007.

Wayne County's slowdown in out-migration could signal a stabilization of population losses in Detroit, said Kurt Metzger, founder of Data Driven Detroit and mayor of Pleasant Ridge. Census data show the number of residents that have left the county as a result of domestic migration has dropped from its recent high of 24,122 between 2010 and 2011 to 15,446 last year.

Related: Look up population for every U.S. county

Only a handful of the nation's 45 counties with more than a million residents lost population last year, including Cook County, Ill.; Wayne County, Mich.; Cuyahoga County, Ohio; Allegheny County, Pa., and Suffolk County, N.Y.

In Michigan, Ottawa County, near Grand Rapids, had the largest population increase on a percentage basis at 1.2%. Ontonagon County, located in the Upper Peninsula, had the largest population decline of 2.5%.

A majority of U.S. metro areas saw population growth last year and some Michigan metro areas climbed as well. The Grand Rapids metro area, which includes Barry, Kent, Montcalm and Ottawa counties, grew the fastest at 0.9%. The Kalamazoo and Lansing-East Lansing metro areas had growth rates of 0.4%. The Ann Arbor metro area, which includes just one county, Washtenaw, increased by 0.5% or 1,851 residents for a total population of 358,880 in 2015.

Metro Detroit's population remained relatively flat, gaining 563 residents at about 4.3 million residents in 2015. Among Detroit metro area counties, Livingston had the fastest growth last year at 0.9%, an additional 1,613 residents.

Macomb County, despite its total population gain of 0.4% or 3,204 residents last year, experienced a change in migration patterns, "reversing its status as a domestic magnet county,” Metzger said. After three years of averaging about 2,000 new residents moving to Macomb County from other parts of the state and country, the 2014-2015 period marked a loss of 1,014 people, according to Metzger.

Lapeer and Oakland counties had population increases of 0.2% last year, adding 174 and 2,407 residents, respectively. Oakland County fell from the 32nd most populous county in the U.S. to 33rd last year at 1.24 million residents, surpassed by Franklin County (Columbus), Ohio.

St. Clair County's population was estimated at 159,875 last year, a loss of 162 people or 0.1%

Nationwide, the most growth could be found among four Texas metro areas — Dallas, Houston, San Antonio and Austin — that added more people, upward of 400,000, than any state in the country except for Texas as a whole, according to a press release issued by the Census Bureau.

The Census data released today measures population changes at the metropolitan and county level and doesn't break down estimates by city or town. Michigan's slow growth last year of 6,720 residents, an increase of 0.1% between 2014 and 2105, was the fourth year in a row the state saw marginal growth. Last year, the state ranked 39th and 44th last year for numeric and percent population increase, respectively, according to an analysis by state demographer Eric Guthrie.

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Contact Kristi Tanner: ktanner@freepress.com