john vs shitter

john

noun
  • A device or place to urinate and defecate: now usually a toilet or lavatory, but also (dated) a chamber pot or outhouse. 

  • A male mule. 

  • A Western man traveling in East Asia. 

  • A prostitute's client. 

shitter

noun
  • A toilet or lavatory; an outhouse. 

  • One who defecates. 

  • The anus. 

  • Someone lacking skill, especially in a video game. 

  • An objectionable person or thing. 

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