You can't tell that for now as till date i still think 60-70% of investors are from china itself but of course the number is reducing daily and i see more chinese getting some actually sense in them. All bitcoin wants now is investments from people around the world as many are aware but for some reason not investing.
Its always them so far, the Chinese investors and miners. It can only decrease gradually but they still are as we speak. If they can talk to one forum and control the market they easily can and will absorb all the USD if they can. It looks like they can control the world with it if now being solved by PBOC. The world is a better place without a a group of people that will control us, its one of the reason why we got into decentralized currencies.
china is only holding the greater % of mining currently, for trading they are behind japan already, and many indian people are entering the market, if the value grow more, it mean that more people are trading bitcoin
actually china people are in high numbers, if there will be more interest there they can still control the big % of the market
but apparently not all chinese are buying bitcoin, it's the opposite very few of them(in comparison with how many they are) are buying many are in the mining scene
Also saw that lately, bitflyer.jp has the top volume.