corn on the cob vs sorghum

corn on the cob

noun
  • Cooked ears of corn (maize, specifically sweet corn). 

sorghum

noun
  • Sorghum syrup. 

  • A cereal, Sorghum genus and species, the grains of which are cultivated to make flour and feed cattle. Almost all cultivated ones as well as some wild ones belong to the species Sorghum bicolor (syn. Sorghum vulgare). 

How often have the words corn on the cob and sorghum occurred in a corpus of books? (source: Google Ngram Viewer )