maravedi vs mustard seed

maravedi

noun
  • A very small quantity or value; the least possible amount. 

  • A former Spanish coin and unit of currency, originally issued in gold but later in silver and copper, discontinued in 1848. 

mustard seed

noun
  • A small amount. 

  • Small lead shot, usually of size No. 12, used for shooting birds and other animals at close range. 

  • A small, round seed of the mustard plant. 

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