bravity vs valour

bravity

noun
  • Synonym of braveness 

valour

noun
  • Strength of mind in regard to danger; the quality which enables a person to encounter danger with firmness 

  • Individually sustained verve or passion. 

  • Value; worth. 

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