prowess vs valiancy

prowess

noun
  • An act of distinguished bravery or courage; a heroic deed. 

  • Distinguished bravery or courage, especially in battle; heroism. 

  • Skillfulness and manual ability; adroitness or dexterity. 

  • An act of adroitness or dexterity. 

valiancy

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