attempt vs deathblow

attempt

noun
  • An assault or attack, especially an assassination attempt. 

  • The action of trying at something. 

verb
  • To try. 

deathblow

noun
  • A strike or blow that leads to death, especially a coup de grace. 

  • Something that prevents the completion, or ends the existence, of a project etc.; a fatal setback. 

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