bottle deposit vs refund

bottle deposit

noun
  • A monetary deposit collected at the point of sale when a bottled beverage is purchased, and fully or partially refunded when the empty bottle is returned. 

refund

noun
  • An amount of money returned. 

verb
  • To return (money) to (someone); to reimburse. 

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