crude oil vs margarine

crude oil

noun
  • Unrefined oil; as it is found underground, consisting mainly of hydrocarbons. 

margarine

noun
  • A spread, manufactured from a blend of vegetable oils (some of which are hydrogenated), emulsifiers etc, mostly used as a substitute for butter. 

How often have the words crude oil and margarine occurred in a corpus of books? (source: Google Ngram Viewer )