controvert vs refute

controvert

verb
  • To argue against (something or someone); to contradict, to deny. 

  • To dispute, to argue about (something). 

  • To be involved or engaged in controversy; to argue. 

refute

verb
  • To deny the truth or correctness of (something). 

  • To prove (something) to be false or incorrect. 

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