Cimmerian vs pitch dark

Cimmerian

noun
  • Any of the mythical people supposed to inhabit a land of perpetual darkness. 

  • the prophetic priestess presiding over the Apollonian Oracle at Cimmerium in Italy. 

  • one of the Cimmerii, ancient equestrian nomads of Indo-European origin 

adj
  • Pertaining to the ancient Cimmerians. 

  • Characteristic of Cimmeria; especially describing particularly dense darkness etc. 

  • related to the prehistoric continent of Cimmeria 

name
  • the language of the Cimmerians, possibly belonging to the Iranian branch 

pitch dark

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