fifty-fifty vs occurrence

fifty-fifty

adj
  • Half and half. 

  • Used to describe 2 possible outcomes as being equally likely 

noun
  • A challenge between two opposing players, where both have an equal chance of taking possession. 

adv
  • In half: in two equal parts, shares, etc. 

occurrence

noun
  • The lexical aspect (aktionsart) of verbs or predicates that change in or over time. 

  • An actual instance when a situation occurs; an event or happening. 

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