Dulles is one of the three major airports in the larger Baltimore–Washington metropolitan area with more than 24 million passengers a year. Dulles has the most international passenger traffic of any airport in the Mid-Atlantic outside the New York metropolitan area, including approximately 90% of the international passenger traffic in the Baltimore–Washington region. On a typical day, more than 60,000 passengers pass through Dulles to and from more than 125 destinations around the world. The airport is considered the region's international air hub, with dozens of nonstop international flights. Increased domestic travel from Reagan National Airport has eroded some of Dulles's domestic routes. Dulles overtook Reagan in total enplanements in 2019. In 2018, Dulles Airport surpassed Ronald Reagan Washington National Airport (DCA) in yearly passenger boardings after having fewer passengers since 2015. However, it still ranks behind Baltimore–Washington International Thurgood Marshall Airport (BWI) in total annual passenger boardings. Dulles is a hub for United Airlines and is frequently used by airlines which United has codeshare agreements with, mostly composed of Star Alliance members like Saudia and Lufthansa.