One thing I didn't know until I did, surprisingly late in my career, was that reports written later have no impact on the RSCA for reports written earlier.
So it is mathematically possible to have every report you've ever written be at or below your RSCA.
And of course the opposite (everybody is above average).
So it is mathematically possible to have every report you've ever written be at or below your RSCA.

And of course the opposite (everybody is above average).