Baltimore City and Baltimore County lost residents faster than anywhere else in Maryland in 2023, continuing a trend of population loss in the city that’s lasted decades and a county trend that started in 2021.

The Baltimores were two of only three counties or county-equivalents to lose population last year, according to new population estimates from the U.S. Census Bureau released Thursday. The city has lost thousands of people per year for dozens of years, and recently has seen a large loss of Black residents to the surrounding counties. Race data wasn’t available in Thursday’s release.

Baltimore County, where population has been slowly shrinking since a dramatic rise in 2020, lost about 1,200 people, a decline of about 0.1% . Though population has declined in the county every year since the pandemic, the rate of decline in 2023 was lower than in 2022.

Baltimore City lost nearly 4,000 people between July 2022 and July of last year. That’s a 0.7% decline. The city has lost more than 20,000 people since the Decennial Census in 2020, and more than 60,000 since 2010.

The much smaller Garrett County, in the northwestern corner of the state, also lost population. Every other county was either flat or gained population.

Much of that population loss has come from domestic migration, one of the major components of population change. Simply put, more people are moving out of Baltimore than are moving in, especially from within the United States. Black Baltimore residents, especially, have been leaving the city in large numbers in recent years, and heading to the suburbs. That may still be happening, but without racial data, we can’t say for sure that’s what happened in 2023.

Baltimore City saw a net loss of nearly 6,400 people from domestic migration in 2023 alone. That number was offset somewhat by an influx of foreign immigrants and a slight gain through natural increase — the number of births compared to deaths.

On the other end of the spectrum, Frederick County remains the fastest growing county in Maryland. It grew by 2% last year, and has added a total of nearly 22,000 people, a growth rate of 8% since 2020. Both figures lead the state.

Queen Anne’s, Somerset and Charles counties all grew by more than 1%.

Overall, Maryland’s population grew by more than 16,000 people from 2022 to 2023, according to the census estimates. That’s about a quarter of a percent, pushing Maryland’s population to nearly 6.2 million people, its highest total ever. But the state’s growth lagged behind the national average population growth rate of about half a percent. And like Baltimore, Maryland saw major losses in population through domestic migration. The state saw 30,000 fewer people move in than moved out within the U.S. in 2023, the sixth largest loss of population from migration of any state.

Only two Maryland Counties — Frederick and Charles — saw net increases of at least 1,000 people from domestic migration.

The Census Bureau’s yearly population estimates, an important tool for local governments across the country to assess how to allocate resources, are generated based on a calculation that starts with population based on the last national census and factors in births, deaths, and domestic and international migration in the interim.