Age of first-time mothers in America, 1980 versus 2016:

In 1980, the modal age of first-time mothers was 19, and the percentage of 16-year-old first-time mothers was almost double that of 30-year-old first-time mothers.

In 2016, the percentage of 18- and 30-year-old first-time mothers is practically equal, and 20-years-old has taken the modal spot from 28-years-old by a minute fraction of a percentage.

New York Times (2018) #fertility