First graph is all reported child sexual abuse cases that were substantiated. You can see the full tables in the ACF website, and in 2021 specifically there were 59,328 CSA cases in the U.S. that were substantiated.
The percentage of kids who've officially reported sexual abuse actually seems to be decreasing considering not only the decrease you see in the graph (and it decreased further in 2022 to 59,044 cases), but also because in the Youth Risk Behavior Survey the percentage of teens who said they've experienced some kind of sexual violence increased from 9.7% in 2017 to 11% in 2021, and for rape specifically it went from 7.4% to 8.5%.
Ages ago I posted a meme to r/PoliticalCompassMemes about how Lauren Boebert was happy to become a grandma at 36 when her 17 year old son had a kid, which is obviously very weird and unhealthy. Like clockwork, a lot of 'AuthRight' flairs came to the comments to defend teen pregnancy. You can see the post here if you really want to have a look at the hellhole that is PCM: https://redd.it/11n2z00
So yeah, it pretty much is a feature for them.