margarine vs petrol

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. 

petrol

noun
  • petroleum, a fluid consisting of a mixture of refined petroleum hydrocarbons, primarily consisting of octane, commonly used as a motor fuel. 

  • A motor vehicle powered by petrol (as opposed to diesel). 

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