best man vs master of ceremonies

best man

noun
  • The primary attendant to the groom in a wedding ceremony. 

  • Used other than figuratively or idiomatically: see best, man. 

master of ceremonies

noun
  • Someone who acts as a host at a formal event. 

  • Someone who conducts a programme of varied entertainment, for example by introducing performers to the audience. 

  • A rapper. 

How often have the words best man and master of ceremonies occurred in a corpus of books? (source: Google Ngram Viewer )