come back vs go again

come back

verb
  • To return to one's possession, especially of memories. 

  • To retort. 

  • To return to a former state, usually a desirable one; to become fashionable once more. 

  • To return to a place. 

go again

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