convocation vs viewership

convocation

noun
  • An assembly or meeting. 

  • The act of calling or assembling by summons. 

  • An assembly of the clergy, by their representatives, to consult on ecclesiastical affairs. 

  • An academic assembly, in which the business of a university is transacted. 

  • A flock of eagles. 

viewership

noun
  • collectively, the viewers of a television program or other video broadcast 

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