`As of 2021, 25% of 40-year-olds in the United States had never been married. This was a significant increase from 20% in 2010.
https://www.pewresearch.org/short-r...-year-olds-in-the-us-have-never-been-married/
https://www.pewresearch.org/short-r...-year-olds-in-the-us-have-never-been-married/