WASHINGTON, DC. : The flag of the District of Columbia and the American flag in Washington, DC. (Jonathan Newton / The Washington Post)

Census estimates released Tuesday show D.C.’s population is 681,170 — the highest in about four decades.

The figures, released by the U.S. Census Bureau, showed the city gained more than 10,000 residents since last year — an average of about 900 new residents per month — and about 79,000 residents since 2010, or an increase of more than 13 percent.

Mayor Muriel E. Bowser (D) praised the news.

“Our growth in population shows that Washington, DC continues to be an attractive place to live, work and start a family,” Bowser said in a statement. “Our neighborhoods continue to grow safer and stronger, and our schools continue to enroll more students and improve outcomes.

The Census Bureau said the largest factor in D.C.’s population growth was migration — people moving to the city from elsewhere. Almost 6,400 new residents moved to D.C. between July 2015 and July 2016, including more than 4,100 from abroad.

D.C. is in the middle of a bit of a baby boom, meanwhile, with almost 9,800 births so far in 2016 — 122 more than last year.