Ragnarok, dead? Last I heard that was one of the most congested servers, although it did become part of the European server group so maybe you were just playing during EU 'quiet time'?

We now have the world-visit system so that you are free to 'server hop' to any server on your data centre, although there are restrictions to what you can do when you are not on your 'home server' (such as you cannot join a Free Company on another server when visiting that server). To access it all you have to do is click on the aetheryte in either Limsa Lominsa, Gridania or Ul'dah and select the server you want to visit (it's how you return to your home server as well).

Also don't listen to the so-called unofficial censuses, they're usually biased and only collerate data based on certain parameters (usually endgame or story completion) to try and determine 'active' players instead of just grouping all player data on that server.

Either way, welcome back to Eorzea!