mettle vs pugnacity

mettle

noun
  • A quality of endurance and courage. 

  • Good temperament and character. 

adj
  • Spirited, vigorous, stout-hearted. 

pugnacity

noun
  • The act or characteristic of being aggressive or combative. 

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