AMCAS has everything!
Actually, I have no idea about IIs, but schools certainly have nothing to hide.
Anyway, it's really not a race thing. There are a tiny fraction of top applicants of all races who do very well.
They are over represented on SDN, in addition to whoever is exaggerating how well they are actually doing. In any event, what's the difference?
High stat URMs who check all the other boxes do very well mainly because there are so few of them. They are no more representative of URMs as a whole than ORM or white applicants with amazing applications are of their groups. They are unicorns, their percentage generally tracks that of unicorns, and they perform accordingly.
What IS definitely reported is As. As has been widely reported on SDN, 64% received zero As last cycle. Every cycle, around half of all matriculants only have one A, and that includes last minute As off a WL. Beyond that, other than benchmarking yourself against everyone else, what's the difference how many people receive how many IIs, or As?
Until it's over, you honestly cannot tell how you are going to do based on your number of IIs. The average is one A for every 3 IIs, but there is a very wide variance based on just what schools you have IIs from, as well as your relative position in each school's pool. Plus, of course, how you perform as an interviewee. People with 7 As end up on 7 WLs and become reapplicants, while others with 3 IIs end up with 3 As.
If it helps, something I saw a few years ago suggested that the numbers decrease somewhat geometrically after 1 A, until you literally have a small handful of people with 10+ As (i.e., around 10K people with one A, 5K with 2, 2K with 3, 1K with 4, 0.5 K with 5, 0.2K with 6, etc.).