Cook County experienced its first population loss since 2007 and the largest drop of any U.S. county over the past year, according to new Census Bureau estimates.
Between July 1, 2014 and July 1, 2015, the county lost 10,488 residents. Wayne County, Michigan (home to Detroit), had the next lowest total, losing more than 6,000 people.
The Chicago metropolitan area, which includes parts of Indiana and Wisconsin, also saw a population decrease of 6,263, more than any other metro area.
The estimates end a trend of slow but steady growth in both Cook and Chicago. In each case, the drop was driven by people choosing to move to other areas within the U.S.
Cook County saw more births than deaths over the past year and gained 22,000 migrants from other countries. That wasn’t enough to make up for more than 55,000 people who moved away from Cook County within the United States.In the Chicago metro area that figure was more than 80,000.
Overall, all but 16 of Illinois’ 102 counties lost population in the past year. Only Kane, Will, Kendall and Champaign counties gained more than a thousand residents.
Those figures are in contrast to areas in the South and West that continue to see huge population growth. In the past year, four of the fastest-growing counties were in Texas and three were in California.
Chris Hagan is a data reporter with WBEZ. Follow him @chrishagan.