acerbate vs consternate

acerbate

verb
  • To exasperate; to irritate. 

  • To make bitter or sour. 

adj
  • Embittered; having a sour disposition or nature. 

consternate

verb
  • To cause consternation in; to dismay. 

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