Australian rules football vs footy

Australian rules football

noun
  • A variety of football devised in Australia. 

footy

noun
  • Football (association football) (soccer in US, Canada, Australia, New Zealand) 

  • A football fan. 

  • The game or sport of football, usually Australian rules football or rugby league, but not soccer 

  • The ball used in a game of footy. 

  • A short sock. 

How often have the words Australian rules football and footy occurred in a corpus of books? (source: Google Ngram Viewer )