I counted the population on Runnyeye at 21:00 GMT and found 4257 people online. Being bored, I made a graph by level and class which I am linking here (if it works):
Runnyeye Character Count by Class & Level
Note this is peak hours since this was initially designated the euro-english server. The spikes at 3 and 6 are funny since they represent people just starting the tutorial (3) and people who are working on citizenship quests (6). Max level was 25 with 4 people.