I have to say that number is higher than I expected. 50, 60% sure but 80% is almost all of it.
A lot of NXT goes to the Chinese as well. What can you say, other than that they love to speculate on new cryptocurrencies

That's just 80% for the Yaun-BTSx. They take up another 18% or so with BTC trades (which fair enough some of those people could be American or European).
The biggest non-Chinese exchange only does like 1% of overall volume being Poloniex.
So yeah 80% - 99% of buyers are Chinese
I'm European and I rarely trade at Poloniex but rather often on BTER and BTC38, not with 元 though, indeed. I have a background in East Asia but I know countless Westeners who happen to trade at BTER. Anyhow you're definitely right in that BTSX/CNY volume has been remarkable these days, massive buy support indeed.