bravery vs mettlesomeness

bravery

noun

  • Being brave, courageousness. 

  • A brave act. 

  • Splendor, magnificence. 

mettlesomeness

noun

  • The quality of being mettlesome. 

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