Siberia vs certitude

Siberia

name
  • The region of Russia in Asia, stretching from the Urals to the Pacific Ocean. 

noun
  • A cold, inhospitable place or place of exile. 

certitude

noun
  • Something that is a certainty. 

  • Sureness, certainty. 

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