The Dallas-Fort Worth area grew more in the last decade than any other metropolitan region in the country, according to new population estimates released by the federal government.

The metroplex’s population rose by more than 1.2 million between 2010 and 2019, the U.S. Census Bureau reported March 26.

Three North Texas counties were among the 10 American counties with the largest population gains in that time: Collin, Dallas and Tarrant counties.

The estimates were released less than a week before April 1, the reference date for this year’s census count.

Every 10 years, the federal government attempts to count every resident in the United States. This count determines how billions of dollars in federal funding are allocated, informs public and private decision-makers, and determines congressional representation.

Residents across the U.S. have begun receiving notices in the mail with instructions on how to complete the census online, by mail or over the phone.

Their responses to the questionnaire—which covers how many people live at each residential address and other topics—are intended to be accurate as of April 1, also referred to as Census Day.

While the reference date for census questions remains the same, organizers have adjusted the schedule to reflect the disruptions imposed by the coronavirus.

Mailers were sent to residences in mid-March. The bureau initially planned to begin nonresponse followups in early April but pushed it to early May, citing concerns for its census takers who go to door-to-door collecting responses from nonrespondents.

The bureau plans to complete its count by mid-August, an extension from its original date of July 31, the release said.

The bureau is still on schedule to send the final counts to the president by the end of 2020 and deliver redistricting counts to states by April 2021, it said.

Ali Linan contributed to this report.