billfold vs carton

billfold

noun
  • A small, folding sleeve or case designed to hold paper currency, as well as credit cards, pictures, etc. 

carton

noun
  • An inexpensive, disposable box-like container fashioned from either paper, paper with wax-covering (wax paper), or other lightweight material. 

  • A cardboard box that holds (usually 24) beer bottles or cans. 

  • A pack of cigarettes, usually ten, wrapped in cellophane or packed in a light cardboard box. 

verb
  • To put in a carton. 

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