Ranking in Tycoon, inefficient airline?

In the rankings, I'm in the 3000s. I noticed that people just ahead of and behind me have mostly less than half my airline's value, a third of the routes, and half the fleet size. Is my airline inefficient at making money?

I have 1150 routes and 1800 planes (about 1500 of them are in use) and a structural profit of 550 million.

I know it's not good having about 300 to 400 unused planes sitting around, but is that the only reason?