bowls vs volleyball

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. 

volleyball

noun
  • The inflated ball used in such a game. 

  • A game played on a rectangular court between two teams of two to six players which involves striking a ball back and forth over a net. 

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