cognac vs vodka

cognac

noun
  • A brandy distilled from white wine in the region around Cognac in France. 

vodka

noun
  • A clear distilled alcoholic liquor made from grain mash. 

  • Neutral spirits distilled (or treated after distillation) so as to have no distinctive character, aroma, taste, or color. 

  • A serving of the above beverage. 

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