conclude vs start the ball rolling

conclude

verb
  • To shut off; to restrain; to limit; to estop; to bar; generally in the passive. 

  • To come to a conclusion, to a final decision. 

  • To end; to come to an end. 

  • to deduce, to infer (develop a causal relation) 

  • To bring to an end; to close; to finish. 

  • To bring about as a result; to effect; to make. 

start the ball rolling

verb
  • Synonym of get the ball rolling. 

How often have the words conclude and start the ball rolling occurred in a corpus of books? (source: Google Ngram Viewer )