PDX airport passenger traffic, which had already dropped 2.4% in 2008, nosedived another 9.6% in 2009 (its biggest decline of the decade) when total U.S. commercial traffic dipped just 5.3%. The Portland airport’s loss of Mexicana and Lufthansa airlines in 2008 and 2009 didn’t help. Regional airports in Eugene, Medford and Redmond fared better, only falling 2.5%, 6.1% and 5.6%, respectively. PDX’s top three airlines remain Horizon, Southwest and Alaska. Southwest was also the No. 1 airline for passengers nationally in 2009.