Tampa International Airport is a hub for Silver Airways. Southwest Airlines has a focus city at the Tampa International Airport. It used to be the main aircraft and maintenance site for World Airways and North American Airlines. Southwest Airlines carries the largest amount of TPA passengers. Southwest has over 90 flights per day, when it is most busy. The airport presently has 71 non-stop destinations. These include international service to Canada, Mexico, Switzerland, the United Kingdom, and to destinations throughout the Caribbean. The airport had 18,815,452 passengers in 2015. It is the 31st busiest airport by passengers moved in North America. 