fire in the belly vs hunger

fire in the belly

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

hunger

noun
  • Any strong desire. 

  • A need or compelling desire for food. 

verb
  • To have a desire (for); to long; to yearn. 

  • To be in need of food. 

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