protagonist vs titlist

protagonist

noun
  • A leading person in a contest; a principal performer. 

  • An advocate or champion of a cause or course of action. 

  • The main character, or one of the main characters, in any story, such as a literary work or drama. 

titlist

noun
  • The holder of a title in a competitive sport; a champion. 

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