c-note vs i

c-note

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

  • A one-hundred dollar banknote. 

i

noun
  • The name of the Latin-script letter I/i. 

character
  • The ninth letter of the English alphabet, called i and written in the Latin script. 

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