Original source:
https://www.edisonresearch.com/infinite-dial-2019/
> Regarding social media, the latest study finds the number of current users of Facebook continues to drop. The study shows an estimated 15 million fewer users of Facebook than in the 2017 report. The declines are heavily concentrated among younger people.
https://www.slideshare.net/webby2001/infinite-dial-2019
Slide 9-14 or so contain the relevant demographic and year-over-year breakout.