completion vs coup de grace

completion

noun
  • The act or state of being or making something complete; conclusion, accomplishment. 

  • The space resulting from such an act. 

  • The conclusion of an act of conveyancing concerning the sale of a property. 

  • The act of making a metric space complete by adding points. 

  • A forward pass that is successfully caught by the intended receiver. 

coup de grace

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