The decadeslong trend of population decline in Berkshire County is showing no sign of slowing, according to the latest figures from the U.S. Census Bureau.

As of July 1, the county had 126,348 residents, according to the bureau's 2019 nationwide estimates released this week.

The report shows a loss of nearly 4 percent since the 2010 census, when the county's population was 131,275. The Berkshire population peaked at 149,402, according to the 1970 census, and has declined steadily since then.

But, there's a sliver of a silver lining in the newly issued estimates: Compared with the 2018 total of 126,313, the countywide count, essentially, was unchanged in mid-2019.

The latest estimated figures also show that Massachusetts gained residents by just over 5 percent, bringing the statewide total to 6,892,503, making the state among 40 in the nation showing an increase since 2010.

The annual estimate from the Census Bureau, including details on demographic, housing, education and in-home technology trends, is based on the government's American Community Survey, state and county housing unit statistics, building permits and other statistics compiled by the bureau.

The numbers reflect an aging Berkshire population, with 23 percent at 65 or older, compared with the statewide level of 16 percent. The under-18 population in the county is put at 17 percent, compared with 20 percent statewide and 22.4 percent nationally.

The county remains mostly white, at 92 percent of the total. But, there was a modest increase in diversity. Hispanic or Latino residents were 5 percent of the county population, up from 3.5 percent in 2010, while the African American population also gained slightly — 3.5 percent — compared with 2.7 percent in 2010.

Among the county's major population centers:

- Pittsfield came in with 42,533 residents as of July 1, down nearly 5 percent from 2010.

- With 12,904 residents, North Adams showed a nearly 6 percent decline since 2010, while Adams, at 8,077, was down nearly 5 percent.

- Williamstown, fueled by expansion of the major employer, Williams College, stood out as the county's only town to gain residents, with 7,993, a nearly 3 percent increase over the past decade.

- Dalton's 6,569 total population reflected a decline of less than 3 percent.

- In South County, the largest town, Great Barrington, had 6,852 residents, a 3.6 percent decline, while Lee, at 5,715, was down nearly 4 percent.

Since the 2019 census estimate does not break out a count for towns with less than 5,000 in population, Lenox didn't make the cut. According to the latest available annual town report, the local census was 4,791 residents in 2018, compared with the U.S. census of 2010, which showed 5,025.

Statewide, despite the overall increase, Massachusetts was among the nation's leaders for residents moving elsewhere, with just over 30,000 people relocating, primarily to southern and southwestern states.

But, thanks to immigration, as well as births outnumbering deaths, Massachusetts notched an increase of almost 10,000 residents last year, compared with 2018.

Because this year's upcoming U.S. census is the official count taken every 10 years, the stakes are especially high for the state, counties, cities and towns, since federal funding distribution and congressional representation depend on population figures.

Massachusetts Secretary of State William Galvin, the U.S. census liaison for the state, has pointed to challenges facing census-takers in Western Massachusetts as well as Cape Cod and the Islands.

Complicating the count, according to Galvin, are issues such as residents who are out of state for up to half the year in the winter and early spring; people who don't get their mail at home; and foreign-born residents who might fear federally hired census workers.

Although much of the census will be taken online, as well as in follow-up U.S. mailings, hired employees will canvas neighborhoods for people who haven't responded.

"I want to make sure everyone gets counted and that Western Massachusetts is not shortchanged by the federal government," Galvin said during a visit to the Big E in Springfield last September.

The nationwide 2019 population estimate shows the rate of U.S. growth is slowing, with 328,239,523 citizens as of mid-2019, an increase of half a percentage point since 2018.

"Annual growth peaked at 0.73% this decade in the period between 2014 and 2015," U.S. census officials stated. "The growth between 2018 and 2019 is a continuation of a multiyear slowdown since that period."

Statewide and national information from The Boston Globe and State House News Service was included in this report.

Clarence Fanto can be reached at, on Twitter @BE_cfanto or at 413-637-2551.