carnet vs rain check

carnet

noun
  • A ticket book, a collection of tickets in the form of a booklet often sold at a discount to single tickets. 

  • An admission pass. 

  • A customs document that allows the temporary duty-free importation of a particular article 

rain check

noun
  • A reissue, at no extra charge, of a ticket for a baseball game or other outdoor event postponed or interrupted because of rain. 

  • to make good on any experience that the customer deems unsatisfactory. 

  • In social interactions, a deferred invitation, or deferred acceptance of an invitation. 

  • to provide a sold-out item or temporarily unavailable service at a later date for the running (usually special) price. 

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