(The Hill) — Older adults now outnumber children in almost half of the counties in the U.S., new data released Thursday from the Census Bureau shows.

About 45 percent of the nation’s more than 3,100 counties reported more residents 65 years or older than those under the age of 18 in 2024, according to a press release. This marks a significant increase from four years prior, when just 31.3 percent of the counties had more older adults than children.

Most of the counties with an older population were located outside of the metro or micro areas, the release states.

Overall, the population of residents over the age of 65 increased by 3.1 percent from 2023 to 2024, now around 61.2 million. On the other side, the population under 18 decreased by 0.2 percent over the last year, sitting around 73.1 million, the bureau found.

The share of older adults in the U.S. has steadily increased since 2004, increasing from 12.4 percent in 2004 to 18 percent last year. The population of children has declined, dropping from 25 percent to 21.5 percent in that same timeframe, the data shows.

In 2022, the nation’s median age hit 38.9 — the highest it had been at that point. The median age has also been rising for decades, spiking from 30 in 1980 to 35 in 2000.

The latest numbers come as statistics show women in the U.S. having fewer children. Last year, the Centers for Disease Control and Prevention (CDC) released a report showing between 2007 and 2022, the nation’s birth rate fell by nearly 23 percent.

“Children still outnumber older adults in the United States, despite a decline in births this decade,” Lauren Bowers, chief of the Census Bureau’s Population Estimates Branch, said in Thursday’s release. 

“However, the gap is narrowing as baby boomers continue to age into their retirement years,” Bowers added. “In fact, the number of states and counties where older adults outnumber children is on the rise, especially in sparsely populated areas.”

A Census Bureau estimate released in 2023 found that the U.S. population was expected to peak in 2080 and then fall by the end of the century.