Owen
I’ll see if I can get the information from a person I know at the FAA. However, I would think that it would be that at least 50% of the US Class D airports would have large air carriers of more than 31 seats going to them. Most D airports I see in the USA are similar to Coffs Harbour, ie. a larger town with RPT jets and a terminal. Come to think of it, it could even be 80% of the 380 USA Class Ds which allow RPT jet traffic.
But what does this have to do with the issue?