Swiss International Air Lines (SWISS) transported 1,586,914 passengers in May, 10.6% more than the same month last year. SWISS also operated more flights in the month: 12,761, a 4.6% increase on May 2017. May systemwide capacity, measured in available seat-kilometres (ASK), was raised 5.1%. Total traffic volume for May, measured in revenue passenger-kilometres (RPK), increased by 6.9%. Systemwide seat load factor for the month improved accordingly, rising 1.4 percentage points from its May 2017 level to 82.2%.