CHICAGO — Cook County's population dropped by more than 21,000, the largest decrease of any county in the country in 2016, according to new U.S. Census Bureau estimates.

Cook County's population is now at 5,203,499, dropping 21,324 from the year before. That's more than 50 percent higher than the drop that occurred in Cook County in 2015.

It is unclear how much of that drain came from Chicago, as city-based estimates are expected to be released later this spring. In 2015, Chicago's population dropped by 2,890, the second-highest drop of any American city.

Rob Paral, a Chicago-based demographer, noted that while a decrease of 21,000 residents is large, it still is only 0.4 percent of the population. He added that potential issues with population loss in the city and suburbs are different.

"The city has more extremes of the haves and have-nots," Paral said, noting that Chicago's black population has been decreasing in recent years.

"The suburbs are aging, where the people are getting older and dying."

Immigrants have helped curb some of the population loss. More than 18,000 people moved from another country to Cook County last year. But Paral said immigration to the Chicago area is still lower than it used to be.

More than 66,000 people moved from Chicago and suburban Cook County to other places in the United States in 2016, according to data.

The county's birth rate exceeded the number of people who died, which accounts for the overall 21,000-person loss.

The number of people who left Cook County is second to Los Angeles County, which saw 75,168 leave. But L.A.'s overall population grew by 25,660.

Patrick Rollens, 34, was one of the people who left Cook County last year. He lived in Chicago for 10 years in neighborhoods like Ukrainian Village and Andersonville before he and his wife sold their Belmont Central home in January 2016 and left for Oregon. He said they wanted to raise their newborn somewhere else.

"We were fed up with Chicago and Illinois and we were looking for a change," Rollens said. "It is difficult to raise a kid in Chicago if you aren't made of money."

Rollens said the suburbs weren't an option since his wife couldn't keep her job as a Chicago Public Schools teacher due to city residency requirements, so the family decided to make a bigger change.

"We were looking to be around fewer people," Rollens said. "The biggest difference now is I can get in the car, drive for 30 minutes and have gone 30 miles."

John Hoffman, 33, traded his Chicago apartment for a similar reason.

Wanting to be closer to art and music, Hoffman moved to the North Side 10 years ago and became known in the local hard-core music scene for fronting the band Weekend Nachos.

John Hoffman and his girlfriend traded in city living for a town home in Naperville last year. [Instagram/John Hoffman]

In 2016, he packed up and bought a town home in suburban Naperville, which straddles Will and DuPage counties, where he lives with his girlfriend and is closer to family.

"My personality type just doesn't match a city landscape, and really never has," he said. "I don't like crowds, or people/society in general for the most part. ... I don't like busy areas or chaotic environments. ... I really prefer things to be as quiet as possible."

There are still some things Hoffman said has taken some adjusting to, like diversity or authentic food.

But Naperville is home to his favorite Mexican haunt.

"So I'll be fine," he said.

Maricopa County, Ariz., gained 81,360 people, the largest increase in the country.