Yes, China is owning nearly 85% bitcoin amount of the world. there are many bitcoin miners in china.
Once the china government warned the bitcoin exchange and yes, this waining made bitcoin down deeply at once. Who can do it?
Yup I heard that n chain many gamblers also there and very large type of bitcoin will happen in China. Maybe you are right in China their numbers of bitcoin miners are there because of that the bitcoin users also high in China. But I don't believe only in China people having 85% of bitcoin amount of the world.
These just random numbers pulled from the ass, nobody can prove exactly plus many bitcoin lost that mined early on