c-note vs gallon

c-note

noun
  • A one-hundred dollar banknote. 

  • The lowest note of an instrument, written below the staff and the D note. 

gallon

noun
  • exactly 4.54609 liters; an imperial gallon 

  • one-eighth of a U.S. bushel or approximately 4.405 liters for dry goods (a "U.S. dry gallon"). 

  • A large quantity (of any liquid). 

  • 231 cubic inches or approximately 3.785 liters for liquids (a "U.S. liquid gallon") 

  • A unit of volume, equivalent to eight pints 

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