Those screenshots don't show anything, every server will have people in top 10 lol, best way to judge server population is group activity rate, and there is massive difference between top servers and dead ones.

http://i.imgur.com/Bsep6WN.jpg

http://i.imgur.com/DVBavoO.jpg

http://i.imgur.com/UGzhJ9Z.jpg

Those are active servers, 1, 2 and 17, compare that to some dead ones and you will see.

Those are examples of big servers, small ones have less total then 2-3 first groups in the big ones.