There was only 1 other passenger on a Sun-Air flight to BLL that I took earlier this year. We were served dinner whilst still on the ground waiting for our ATC slot!

It was supposed to fly from LCY and was never slated to be particularly busy, but most passengers jumped ship (likely for the ex-LHR an hour later) when it was diverted to operate to/from STN.

Was certainly strange turning up to STN for a "BA" flight. I was apparently the check-in agent's first customer of the day and she also later went through security and acted as the gate agent