appendix vs opening statement

appendix

noun
  • A text added to the end of a book or an article, containing additional information. 

  • Any process, prolongation, or projection. 

  • The vermiform appendix. 

opening statement

noun
  • In adversarial legal systems, a statement made by a party at the beginning of a trial or comparable factfinding proceeding, in which that party lays out their case, generally including the points of fact that they intend to demonstrate and to some degree indicating the rhetorical arguments for why they should prevail. 

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