I'm not sure that's quite the question you want to ask because there are lots of categories of appointees -- for example, prior service, recruited blue-chip athletes, etc. -- included in these numbers that presumably your son doesn't fit within. Nevertheless, here is the 2020-21 Common Data Set for USAFA. According to this, 19.7% of the first-year class members who submitted an SAT score (about half) scored between 1000-1199 (and 4% of the half who submitted an ACT score scored between 18-23 composite, which equates to an SAT range of 960-1150).
I really don't know how much comfort that should give you, but there it is.
https://www.usafa.edu/app/uploads/Common-Data-Set-2020-2021.pdf (p.17 if you want to scroll right to it)