push back vs put to flight

push back

verb
  • To postpone. 

  • To refute or argue against a position or an accusation; to express one's own view on a situation. 

  • To summarily expel asylum seekers, especially in violation of the principle of non-refoulement. 

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

put to flight

How often have the words push back and put to flight occurred in a corpus of books? (source: Google Ngram Viewer )