boules vs bowls

boules

noun
  • bowls; a game played with metal balls. 

bowls

noun
  • A ball used in the game of bowls 

  • A precision sport where the goal is to roll biased balls (weighted on one side, and called bowls) closer to a smaller white ball (the jack or kitty) than one's opponent is able to do. 

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