recidivism vs strengthening

recidivism

noun
  • Committing new offenses after a crime committed in the past. 

  • Chronic repetition of criminal or other antisocial behavior. 

  • Returning to a negative behavior after having stopped it for a period of time. 

strengthening

noun
  • The process by which something is strengthened. 

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