It's difficult to figure out who people are on one's own flight. My (Thai) wife and I arrived at Suvarnaphumi last night. The plane (Thai Air 777) from Tokyo was packed to the gills. (As far as I could tell, Thai has no less than 3 classes above Cattle Class, all full. Economy had not a single seat free.)
However, at Immigration, there were no queues of any kind. My wife, with her Thai passport, had to go through the fingers-thumbs-and-face routine just like me. At a guess (and obviously that's all it can be from very superficial observation) a good 60% of passengers were Thai and about 30% Japanese, leaving the rest to be Canadians or Americans.