"Table 4. Top 10 U.S. Airlines, ranked by March 2006 System* Enplanements",,,,, "Passenger numbers in millions (000,000) ",,,,, Mar. 2006 Rank,Carrier,Mar. 2006 Enplaned Passengers,Mar. 2005 Rank,Mar. 2005 Enplaned Passengers, ,,,,, 1,American Airlines,8.7,1,8.7, 2,Southwest Airlines,8.3,3,7.7, 3,Delta Air Lines,6.8,2,8.2, 4,United Airlines,6.1,4,5.7, 5,Northwest Airlines,4.8,5,5.2, 6,Continental Airlines,4.2,7,3.9, 7,U.S. Airways,3.4,6,4.2, 8,America West Airlines,1.9,8,1.9, 9,AirTran Airways,1.8,11,1.4, 10,SkyWest Airlines,1.7,12,1.4, "Source: Bureau of Transportation Statistics, T-100 Market",,,,, * System equals domestic plus international,,,,, Note: Percentage changes based on numbers prior to rounding.,,,,,