Keeping with a three-year downward trend, the Chicago metropolitan area bled residents from July 2016 to July 2017, according to data from the United States Census Bureau.
The Chicago area, which includes counties west of the city and parts of northwest Indiana and southeast Wisconsin, lost an estimated 13,286 residents last year. The area still holds an estimated 9,533,040 people.
Cook County alone lost 20,093 residents, the biggest drop in the country, data showed. But it remains the nation’s second-most populous county.
The Chicago area’s population has been dropping for years, but this drop is the most dramatic yet. From 2014-15 there was a 3,371-resident decrease and 2015-16 saw 11,177 more people leave.
Of the 10 most populous metropolitan areas in the country, Chicago’s was the only population to drop. Dallas' metro area saw the largest gains for the second year in a row, adding 146,238 residents from 2016-17.
“Historically, the Dallas metro area attracts large numbers from both international and domestic migration," Molly Cromwell, a demographer at the Census Bureau, said in a statement. "Many of the other largest metro areas in the country rely mostly on international migration and natural increase for growth."
In general, people are flocking to the south and west regions of the country—especially Texas, census bureau data showed. Eight of the 15 counties with the largest population gains are in the Lone Star State.
Still, Maricopa County, Arizona, saw the largest population gain with an estimated increase of 73,650. Clark County, Nevada, was a distant second with 47,355 residents added.