Next month marks the fourth anniversary of the Airbus A380's entry into service. Since the maiden commercial flight by Singapore Airlines, A380s have carried more than 20 million passengers on flights with SIA and five other operators: Emirates, Qantas, Lufthansa, Air France and Korean Air. 56 A380s are now in service, with approximately ten more to be delivered by the end of the year. A380 operations are clustered around a handful of key international points. A380s currently serve 25 airports on 38 separate routes. Seven airports account for more than half of all A380 routes.