mettle vs mettlesomeness

mettle

noun
  • Good temperament and character. 

  • A quality of endurance and courage. 

adj
  • Spirited, vigorous, stout-hearted. 

mettlesomeness

noun
  • The quality of being mettlesome. 

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