Turkish Airlines, Inc. (Turkish Türk Hava Yolları Anonim Ortaklığı) (THY) is the national airline of Turkey based in İstanbul. It operates a network of scheduled services to 123 international and 32 domestic cities, serving a total of 155 airports, in Europe, Asia, Africa, and the United States. The airline's main base is Atatürk International Airport (IST), İstanbul, with secondary hubs at Esenboga International Airport (ESB), Ankara, and Sabiha Gokcen International Airport (SAW), İstanbul. In 2006 and 2007 it carried 17 million and 19.7 million passengers with total revenues of US$2.3 and US$3 billion, respectively. The airline has around 12,000 employees. As of April 1, 2008, THY is an official member of Star Alliance.