I was wondering about that. It could be that supplies of the new coin are done on an area by area basis, with all production going for distribution in one area. If you can get 6 figures from a die pair, then it may be necessary to see several runs before the averages work out to be 50:50. Are these edges put on in advance or at the time of striking?
For what it's worth, I have 1 smooth right to 11 smooth left.