free pass vs quittance

free pass

noun
  • A document entitling the bearer to free transportation. 

  • An exemption from normal processes. 

  • An intentional walk. 

quittance

noun
  • A discharge from a debt or obligation; a document that shows this discharge. 

  • A release or acquittal. 

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