180 vs retroversion

180

noun
  • An instance of spinning 180 degrees, so that one is facing in the opposite direction. 

  • The friendly welcome was a 180 from what she had been expecting 

  • The exact opposite. 

  • A complete change of direction or opinion. 

retroversion

noun
  • A turning or falling back. 

  • The state or condition of being retroverted. 

How often have the words 180 and retroversion occurred in a corpus of books? (source: Google Ngram Viewer )