sortilege vs witchcraft

sortilege

noun
  • Witchcraft, magic, especially as a means of making decisions or predictions. 

witchcraft

noun
  • The practice of witches; magic, sorcery, or the use of supernatural powers to influence or predict events. 

  • Something, such as an advanced technology, that seems almost magical. 

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