breakfast cereal vs oats

breakfast cereal

noun
  • A food made from processed grains, such as maize, oats, wheat or rice, usually eaten for breakfast with milk and sometimes sugar. 

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 breakfast cereal and oats occurred in a corpus of books? (source: Google Ngram Viewer )