Hyperborean vs freezing

Hyperborean

freezing

adj
  • Zero °C, the freezing point of water. 

  • Suffering or causing frost 

  • Very cold 

noun
  • The change in state of a substance from liquid to solid by cooling to a critically low temperature. 

  • The action of numbing with anesthetics. 

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