The three major ISPs in China just deployed IPv6 in most cities, though IPv6 based routing and DNS is still suboptimal. I don't know how Google generate the ipv6 statistics, but in the case of China it may not be very accurate. Most Google services are blocked there.
I live there and I don't see a change. Other, non-Google counters are also not very optimistic.
EDIT: My bad, I just checked today and there are positive changes - all my connections are now IPv6, mobile and fixed line. The IPv6 speed as opposing IPv4 one is very low though...