push back vs rebut

push back

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

  • 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. 

rebut

verb
  • To drive back or beat back; to repulse. 

  • To deny the truth of something, especially by presenting arguments that disprove it. 

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