The baby boom of the post-World War II era has created a demographic bulge of seniors, both nationally and in Pennsylvania.
New figures released by the U.S. Census Bureau show that in the southeastern part of the state, the biggest boom has been among the 65-and-over crowd.
"When you see population growth in the county, it's coming from us living longer and baby boomers aging out," said Dan Fogarty, the Berks County Workforce Development Board's chief operating officer.
Fogarty was speaking of Berks County, which saw its 65-and-older population grow by 24% from 2010 to 2019.
The same is true of Chester, Montgomery, Delaware and Bucks counties.
Chester County's population grew 5% from 2010 to 2019, but the majority of the growth came in the 65 and older age group, which grew by 37% over nine years.
The population of children 14 and under, meanwhile, fell by 5,506, or 5.4%.
In Delaware County, the 65-and-over population grew by 19%, while that of children and the workforce population of people 15 to 64 fell from 2010 through last year.
Montgomery County saw its workforce population grow by less than 1%, while the population of those 65 and older grew by nearly 25%.
The Census Bureau's annual estimates show population by age and race, as well as Hispanic origin.
The figures are calculated based on the decennial census, plus births, minus deaths and plus net migration in a given year. The estimates provide the basis for the annual American Community Surveys, which go into more detail about population trends.
The Latino population has been on the rise in the last nine years, but in the Philadelphia suburbs, Berks County saw the largest growth.
In 2010, Latinos made up 16.5% of the population; by 2019, it was above 22%. In Bucks, Chester, Delaware and Montgomery counties, Latinos still make up less than 10% of the population.