déjè vu vs mirage

déjè vu

mirage

verb
  • To cause to appear as or like a mirage. 

noun
  • An optical phenomenon in which light is refracted through a layer of hot air close to the ground, often giving the illusion of a body of water. 

  • An illusion. 

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