I've been on two Moscow-Tokyo flights (Aeroflot) that were less than one third full. I've been on a couple of intercontinental flights using Etihad, Swissair,

I've been on two Moscow-Tokyo flights (Aeroflot) that were less than one third full. I've been on a couple of intercontinental flights using Etihad, Swissair, Lufthanza and British Airways between Europe and Asia, most of which were not fully filled for the long legs between major hubs. I've also seen a few full flights, so I guess it depends on luck and the seasons.