Since it's based on Google metrics - what are the stats like for countries where Google is not the most popular search engine? E.g China, Russia and Japan.
Is it really based on Google metrics? Google has been blocked by the Great Firewall on IPv4 networks since last year, but is still reachable via IPv6. So a Chinese who accesses Google either does it with a foreign IP (VPN or proxy), or with an IPv6 address within China. That would put the statistics close to 100% IPv6 usage.