Chart of Glasgow Prestwick Airport busiest routes to and from Glasgow Prestwick (2016)

Reference 1: Total passengers and Change 2015/16.

Reference 2: Barcelona, Málaga, Alicante, Tenerife–South, Faro, Palma de Mallorca, Lanzarote, Gran Canaria, Murcia, Ibiza, Pisa, Rome–Ciampino, Fuerteventura, Malta and Reus.

Source: http://en.wikipedia.org/wiki/Glasgow_Prestwick_Airport