spoiler
Via https://radar.cloudflare.com/adoption-and-usage
Here is a different source with slightly different results https://www.6connect.com/blog/global-adoption-of-ipv6-top-ten-countries/
For fun you can comment your guesses first :)
surprising there’s no china, with billions of connected devices. Maybe you don’t need many public ipv4 when you run a country-wide LAN with limited internet access