gift certificate vs season ticket

gift certificate

noun
  • A gift voucher entitling the bearer to a free product or service, intended to be purchased as a gift. 

season ticket

noun
  • A ticket that is valid for all of the events in a series of related events for which individual tickets would otherwise be needed. 

  • A ticket that is valid for multiple rides (limited by number of rides and/or time of travel) by public transit for which individual tickets would otherwise be needed. 

How often have the words gift certificate and season ticket occurred in a corpus of books? (source: Google Ngram Viewer )