gasohol vs naphtha

gasohol

noun
  • gasoline mixed with ethyl alcohol (ethanol). 

naphtha

noun
  • Any of a wide variety of aliphatic or aromatic liquid hydrocarbon mixtures distilled from petroleum or coal tar, especially as used in solvents or petrol. 

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