pin money vs small change

pin money

noun
  • An allowance of money given by a man to his wife or to other dependents for their personal, discretionary use. 

small change

noun
  • A minor or insignificant amount of money. 

  • Coins of little value kept in one's pocket or bag. 

  • A person or thing of little importance or value. 

How often have the words pin money and small change occurred in a corpus of books? (source: Google Ngram Viewer )