Utah ranks No. 1 among the states for its population growth rate this decade — thanks to its high birthrate plus a strong economy that attracts people from other states and abroad.

Growth slowed a bit here recently — and Utah ranked No. 3 for 2018, according to estimates released Wednesday by the U.S. Census Bureau.

“We added nearly 400,000 people this decade,” the equivalent of adding two cities the size of Salt Lake City, said Pam Perlich, director of demographic research at the University of Utah's Kem C. Gardner Policy Institute.

In just the past year, Utah added 57,987 residents — the equivalent of adding a Taylorsville-size city.

The Census Bureau now estimates Utah’s population at 3,161,105.

(Christopher Cherrington | The Salt Lake Tribune)

That is about 5,500 lower than an estimate of 3,166,647 made earlier this month by the Utah Population Committee, a group set up by the state to use local data to estimate the population as a check on estimates by the Census Bureau. Perlich, a member of the committee, called the difference “very small” for being so far from the latest official Census count in 2010.

Since that Census, Utah has seen a growth rate of 14.4 percent — highest among the states, although the District of Columbia was higher at 16.6 percent. The national average over that time was 6 percent.

Utah led the nation because of its still-high birthrate — even though it has been dropping — and for being a magnet for immigrants, Perlich said.

“We’re still among the very highest in the nation on natural increase,” or having more births than deaths, she said. “And we’ve had really accelerating and robust migration to the state, especially over the past few years.”

Perlich noted that when the last constitutionally required census was conducted in 2010, “it was at the height of the Great Recession, and net migration was minimal everywhere. People were just stuck in place.”

That changed, “especially in Utah where we have one of the strongest economies in the nation,” attracting migrants seeking jobs or education, Perlich said. In 2018, for example, the census figures 43 percent of Utah’s growth came from people moving here.

“In the past, in the old Utah, we depended almost entirely on natural increase for growth,” Perlich said. “We’ve come to increasingly depend upon migration as a driver of it.”

She adds that immigration “really peaked in 2017. It’s strong this year, but it’s down just a little bit.”

Since 2010, a net increase of 113,136 immigrants came to Utah — with 59 percent from other states, and 41 percent from other countries.

Perlich says many international immigrants tend to be at the top or bottom of the economic ladder. Some come for low-skill jobs, and “you have the people who are very high achievers who take those very highly compensated scientific and technical jobs” in such places as Silicon Slopes.

With immigration increases over recent years, Perlich said, “We are on our way to becoming a very large global metropolitan area. We can expect the continued arrival of international people because the labor market is global at this point.”

Perlich said national and state projections show most future growth will “be generated by these diverse populations who immigrate to the country and then have kids.”

For example, the Salt Lake City School District says its students speak 90 languages, and most of its schools now have a majority of students who are minorities.

In 2018, Utah ranked No. 3 for growth at 1.9 percent behind two of its neighbors. Nevada and Idaho led the nation, both at about 2.1 percent.

“It shows the strength of the Intermountain region,” Perlich said.

She adds that Utah’s growth is manageable. “A 1.9 percent rate is not booming population growth. It is sustainable.”