pull back vs pull in one's horns

pull back

verb
  • Used other than figuratively or idiomatically: see pull, back. 

  • To retreat. 

  • To pass (the ball) into a position further from the attacking goal line. 

  • To score when the team is losing. 

pull in one's horns

verb
  • To become less impassioned, aggressive, or argumentative; to exercise restraint; to yield or capitulate. 

How often have the words pull back and pull in one's horns occurred in a corpus of books? (source: Google Ngram Viewer )