air transport vs aviation

air transport

noun
  • The transport of people and/or cargo by air 

aviation

noun
  • Flying, operating, or operation of aircraft. 

  • Industry that produces aircraft. 

  • A cocktail made with gin, maraschino liqueur, crème de violette and lemon juice 

  • The art or science of making and flying aircraft. 

  • aircraft 

How often have the words air transport and aviation occurred in a corpus of books? (source: Google Ngram Viewer )