afterworld vs spiritual world

afterworld

noun
  • A supposed world that is entered after death; the realm of the afterlife. 

spiritual world

noun
  • The afterlife. 

  • A metaphysical plane of existence parallel to the material world and occupied by spirits and other unearthly forces. 

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