kvass vs libation

kvass

noun
  • A fermented cereal-based low alcoholic beverage, often flavored with fruit, honey and herbs. 

libation

noun
  • A beverage, especially an alcoholic one. 

  • The act of pouring a liquid, most often wine, in sacrifice on the ground, on a ritual object, or on a victim, in honor of some deity. 

  • The wine or liquid thus poured out. 

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