Claret vs fervor

Claret

noun
  • someone connected with Burnley Football Club, as a fan, player, coach etc. 

fervor

noun
  • A passionate enthusiasm for some cause. 

  • Heat. 

  • An intense, heated emotion; passion, ardor. 

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