contentment vs rankling

contentment

noun
  • happiness in one's situation; satisfaction 

  • The neurophysiological experience of satisfaction and being at ease in one's situation, body, and/or mind. 

  • The state or degree of being contented or satisfied. 

rankling

noun
  • A sensation that rankles. 

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