12% of Americans are now felons according to The Economist.
Incidentally, the definition that Scalia uses for felon is: A serious crime punishable by death.
Less than half of the Americans convicted of felonys ever serve time.
If that is true and I have no reason to doubt you.....then if one removes children and 90% of women from that pool(since they commit a mere fraction of crime)...then I would guess my surmisal of 3-5% is low by nearly 100% or better.
At the time of the Founding Fathers.