horoscopy vs necromancy

horoscopy

noun
  • The casting of horoscopes. 

  • The aspect of the stars at the time of a person's birth. 

necromancy

noun
  • Synonym of necroposting 

  • Divination involving the dead or death. 

  • Loosely, any sorcery or witchcraft, especially involving death or the dead, particularly sorcery involving raising or reanimating the dead. 

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