So what kind of airplane do you have to fly to be an "airline"? Where is that written down? Many, probably over half, of the commuter (scheduled) operations are turboprop and/or multi-engine and/or multi-crew operations. The single-pilot piston stuff mainly on-demand. Air carrier is what I'm talking about.

So my question is, why wouldn't you consider all of the air carrier fatalities for the accident rate? If you are going to limit to 121, that's fine, just say "121".