(black) magic vs necromancy

(black) magic

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 (black) magic and necromancy occurred in a corpus of books? (source: Google Ngram Viewer )