I play AE pretty frequently and never really care about the ranking feature. In my current game, I was lucky enough to start my airline when the game started and my airline is HUGE now and running very well. I have over 2000 airplanes all of which are paid for, no leases, I have 6000 plus flights a day and 11 hubs and plenty of cash, yet I am only 6th in the ranking. All of the airlines ahead of me have a third of the fleet, hubs and distance. How can I be only 6th? A few days ago I was number 3 and I have only increased my fleet and paid off the airplanes and added new cities. Is it a glitch or is there some specific reason I am falling behind? 

Again, not a huge deal but the number one airline only has 800 airplanes and 6 hubs, I have 2000 planes mostly of which are wide body aircraft! I don't understand the logic. How is valuation determined in the game?

Anyway, still love this game!