A closer look at the data suggests that Americans are not having enough babies to sustain the population.

The total fertility rate for 2018 was 1,729.5 births per 1,000 women aged 15 to 44. (The fertility rate refers to how many children women have overall; birth rate refers to how many children women have in a single year.) But in order for the nation to reproduce its population and remain stable, the CDC says there would need to be 2,100 births per 1,000 women.

That means each woman needs to have at least two babies to replace fathers and mothers, as well as account for extra deaths.