Lead author Dr. Lynnmarie Sardinha said the analysis was motivated in part by a concern that younger women were "falling through the cracks" and not receiving support.
"I was extremely surprised to see what a huge percentage of adolescent girls basically are already being subjected to violence, even before their 20th birthday," she told Reuters. "We are behind where we should be."
The data was based on surveys conducted between 2000 and 2018. Sardinha said data gathered since was still being verified and appeared to show there had been only a "very slight decline."