US Census shows 1st population drop in Illinois’ Cook County

CHICAGO (AP) — New U.S. Census data show Illinois’ Cook County had the largest population decline among counties and its first dip since 2007.

The nation’s second most-populated county lost nearly 10,500 residents between 2014 and 2015, leaving it with 5.2 million residents. The county with the second biggest numeric decline was Michigan’s Wayne County, which lost over 6,600 people.

The U.S. Census on Thursday released the information, which also shows the Chicago metropolitan area with a population drop of almost 6,300 residents. The number of births and new residents didn’t offset the loss.

Experts suggest the reasons for decline include a drop in immigration, an aging Mexican immigrant population and dwindling numbers of black residents.

Los Angeles County in California remains the country’s most populous county with 10.2 million residents.