acerbate vs provoke

acerbate

verb
  • To exasperate; to irritate. 

  • To make bitter or sour. 

adj
  • Embittered; having a sour disposition or nature. 

provoke

verb
  • To cause someone to become annoyed or angry. 

  • To bring about a reaction. 

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