die hard vs fight back

die hard

verb
  • To be slow in changing or disappearing. 

  • To die only after a desperate struggle for life. 

fight back

verb
  • to overturn a losing deficit. 

  • to counterattack; to resist an attack. 

  • to defend oneself by fighting. 

  • to repress; to struggle to repress. 

How often have the words die hard and fight back occurred in a corpus of books? (source: Google Ngram Viewer )