chicken feed vs mintage

chicken feed

noun
  • A very small or insignificant quantity, especially of money. 

  • Food (usually grain) given to poultry. 

mintage

noun
  • Coins collectively; specie 

  • The batch of coins minted at one time 

  • The fee paid to a mint 

  • The process of minting coins 

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