Globally, people 65 and older now outnumber people ages 5 and younger for the first time in recorded history, a new report by the U.S. Census shows. 

Fertility rates across the globe, a term for the number of offspring women have, and increased longevity, are leading to a demographic inversion that's likely to only increase over time, Axios reported. 

According to the report, in 2023, more than 71% of the world's population lived in countries with fertility rates at or below the replacement level — the point by which the population remains steady — of 2.1 births per woman. That's an increase from 45% a decade earlier. 

The population of those over 65 is projected to grow from 852 million in 2025 to 2 billion in 2060. In that time, the total global population is expected to rise from 8.13 billion to 10.23 billion by 2060.