Server Population is not near as bad as people think seriously check this out. This site allows you to see any servers population for a duration of chosen time.
http://www.torstatus.net/the-harbinger/history/7d#!/the-swiftsure/history/7d
I found this site and it's pretty accurate but your not seeing the whole population due to people logging on and off. Not everyone is on at the exact same time. Although as my previous post I still agree with having server transfers due to discovering friends on other servers and such.