Harris County’s eight-year run as the nation’s fastest-growing county has ended, according to estimates released by the U.S. Census Bureau on March 23. Maricopa County in Arizona, which is home to Phoenix, has taken its place as the county with the highest annual population growth.

Between July 1, 2015, and July 1, 2016, Harris County—now the second fastest-growing county in the U.S.—gained 56,587 people, an average of 155 people per day. Most of the growth took place in unincorporated areas, which include Spring and Klein, county officials said.

Nearly 28,000 residents migrated to Harris County from outside of the U.S. over this time. Meanwhile, the natural increase—total births minus total deaths—accounted for a population increase of roughly 46,000.

The Harris County Budget Department released its annual population report in late February, showing unincorporated parts of the county now contain 43 percent of the population. More than 80 percent of the county’s growth since 2001 has taken place in unincorporated areas, Harris County Precinct 4 Commissioner Jack Cagle said.

According to the report, if the unincorporated parts of Harris County were its own city, it would be the fifth-largest city in the U.S.

“There are some who would say the unincorporated [parts of the county are already] larger than the city,” Cagle said.

Harris County remains the nation’s third-largest county overall with 4.7 million people, closely followed by Maricopa County in fourth place with 4.2 million people. Los Angeles County still sits in the No. 1 spot, and Cook County in Illinois is second.

Dallas-Fort Worth-Arlington and Houston-The Woodlands-Sugar Land were the two metropolitan areas with the most total population growth between 2015 and 2016, each increasing by more than 100,000 residents.

Find more highlights from this year’s report at www.census.gov.

Additional Reporting By Vanessa Holt