extirpate vs rub out

extirpate

verb
  • To surgically remove. 

  • To destroy completely; to annihilate, to cause to go extinct locally. 

  • To pull up by the roots; uproot. 

rub out

verb
  • To delete or erase or remove (something) by rubbing. 

  • To kill, especially to murder. 

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