Question: Phoenix–Mesa Gateway Airport is a base for a low-cost airline that has how many employees?
Sentence (from "Phoenix–Mesa Gateway Airport"): Phoenix–Mesa Gateway Airport (IATA: AZA, ICAO: KIWA, FAA LID: IWA) , formerly Williams Gateway Airport (1994–2008) and Williams Air Force Base (1941–1993), is in the southeastern area of Mesa, Arizona, and 20 mi southeast of Phoenix, in Maricopa County, Arizona.
Relevant evidence: No