In Y cabin; Majority on CA are Chinese.
In Premium Cabins on CA it's about 50/50 depending on the route.
This is rough view from 10 flights on CA over the last 3 years.
I flew SYD-PEK last year and 10 non Chinese and one Chinese in Biz. The rest of the plane had no more than 15-20 Non Chinese board (from what I could see at Boarding) - rest of Y was Chinese