contribution vs pin money

contribution

noun
  • An amount of money given toward something. 

  • Something given or offered that adds to a larger whole. 

  • The act of contributing. 

  • The taking part, often with the idea that it has led to (scientific etc.) progress. 

pin money

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

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