Here's Why Airplanes Are So Crowded These Days

Times are tough for airlines, and one of the culprits is high fuel costs: Filling tanks represented 33 percent of the global industry's operating costs, according to the International Air Transport Association.

Airlines can't control the price of fuel, but they can work to reduce how much much they use. One way to do that is to operate fewer flights.

Airport flight departure data from 2007 and 2012, published by the Wall Street Journal, makes it clear that's exactly what they've done.

We pulled the numbers for the 20 airports with the most departures in 2012 and put them in this chart (you can click to enlarge).

The bars going to the left of center indicate a drop in takeoffs. Bars going to the right represent a rise.

Nearly all of them are headed left.

So it's easy to see why planes today are so horribly crowded: Airlines are operating fewer flights, and meeting rising passenger demand by doing everything in their power to pack each one to the gills.