Hadean vs Tartarean

Hadean

adj

  • Pertaining to Hades or hell. 

  • Of, or relating to the geological eon. 

name

  • The Hadean eon; part of the Precambrian supereon, spanning from around 4.6 to 4 billion years ago. 

Tartarean

adj

  • Of or relating to Tartarus. 

noun

  • A native or inhabitant of Tartarus. 

  • A native or inhabitant of Tartary. 

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