fire in the belly vs initiative

fire in the belly

noun
  • The emotional stamina and vigor, passion, or inner drive to achieve something, to take action, etc. 

initiative

noun
  • The ability to act first or on one's own. 

  • An issue to be voted on, brought to the ballot by a sufficient number of signatures from among the voting public. 

  • A new development; a fresh approach to something; a new way of dealing with a problem. 

  • A beginning; a first move. 

adj
  • Serving to initiate; inceptive; initiatory; introductory; preliminary. 

  • In which voter initiatives can be brought to the ballot. 

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