coup de grâce vs culmination

coup de grâce

noun
  • A remarkable finishing action. 

  • A final blow or shot given to kill a wounded person or animal. 

culmination

noun
  • Attainment or arrival at the highest pitch of glory, power, etc. 

  • The attainment of the highest point of altitude reached by a heavenly body; passage across the meridian; transit. 

  • Endpoint (usually good) arrived at after some series of actions or events, or some period , usually after the series or period has ended. The sum of something. 

  • A ceremony marking the completion of studies at an elementary school, middle school or junior high school, the term "graduation" being reserved for high school. 

How often have the words coup de grâce and culmination occurred in a corpus of books? (source: Google Ngram Viewer )