Some got to be gone before the other. Said that, A/C/S are the best letters in English, that is why they are gone first. Out of 7k or so names, only 49 got any A, 208 got any S, and 293 got any C in them.
And A thru F are pretty much done, except for the following three
cxkz
exfj
fwpz
Then K/W are gone for some time now.
G thru J will be gone any time now. So is T.
Soon all will be gone....