At warcraftrealms.com you can see activity ratios, overall populations, and many other charts for all realms. Blizzard has never release census information and I really doubt that they ever will because it exposes information about population imbalances and the number of subscribers in the game.
This site no longer has profile information because the Armory does it extremely well.
I personally use this site to look up the player activity ratios. It is interesting to see this information. Others use it as a source of information for when they choose to create characters on a realm as well. It is as accurate as possible, but there are some realms that need more people to submit their data. For example, the realm you play on is in need of Horde submissions to make the activity ratios more accurate.
http://www.warcraftrealms.com/census.php?serverid=790
There are some of us here who make alts on realms so that a census can be gathered on that realm to help with the accuracy. The community is what makes this site what it is!
I hope this information has been helpful. If not please ask more questions!