instauration vs introduction

instauration

noun
  • restoration after decay or dilapidation; renewal; repair 

introduction

noun
  • A written or oral explanation of what constitutes the basis of an issue. 

  • The act or process of introducing. 

  • A means, such as a personal letter, of presenting one person to another. 

  • An initial section of a book or article, which introduces the subject material. 

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