If you sort the member list by number of posts, you can see the ranks pretty clearly:
Elder Loremaster: probably 10000+
Loremaster: 5000+?
Sage: 2500+
Navigator: 1500+
Revered Elder: 1000+
Wise Elder: 800+ (or maybe 750?)
Senior Adept: 500+
Adept: 300+
Seeker of Wisdom: 200+
Initiate: 100+
Neophyte: 10+
Apprentice: 1+
Lurker: 0