mustard seed vs oats

mustard seed

noun
  • A small, round seed of the mustard plant. 

  • A small amount. 

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

oats

noun
  • Seeds of an oat plant, especially prepared as food. 

  • A mass of oat plants (genus Avena, especially Avena sativa). 

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