All of those numbers are ridiculous for all the aircraft mentioned.
But for purposes of comparison of supersonic aircraft, how many hours of maintenance for every hour of flight for the Concorde?
I’m sure it wasn’t 10, 15, 20, or 30.
I’ve read 18 for the Concorde. And I’m sure the numbers are all ridiculous. But that’s not important for a comparison. It’s important that all the ridiculous numbers are compiled the same way. Apples to apples.