finale vs summation

finale

noun
  • The chronological conclusion of a series of narrative works. 

  • The grand end of something, especially a show or piece of music. 

summation

noun
  • summarization; summary; summing up. 

  • summing; summing up; adding (adding up) of a series of items. 

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