This is not an official report nor reliable benchmark. The testing environments are vary. These EC2 latencies are measured by http://aws-latency.altaircp.com/ Thanks to my friends!
If you want to add a result from your location, feel free to comment on this gist. Please note that you need to try it several times to get an accurate result.
Asia Pacific (Seoul) ap-northeast-2 19ms
Asia Pacific (Tokyo) ap-northeast-1 92ms