go back vs turn back

go back

verb
  • To return to a place or state after having been there at a previous time. 

  • To have known each other for a certain length of time. 

  • To extend into past time. 

  • To go back on. 

turn back

verb
  • To return to a previous state of being. 

  • To cause to reverse direction and retrace one's steps. 

  • To reverse direction and retrace one's steps. 

  • To prevent or refuse to allow passage or progress. 

  • To adjust to a previous setting. 

  • To fold something back; to fold down. 

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