healer vs shaman

healer

noun
  • One who heals, especially through faith. 

  • Anything that heals; a medicine that heals some wound, injury, ailment, or disease. 

shaman

noun
  • A traditional (unscientific) faith healer. 

  • A member of certain tribal societies who acts as a spiritual and, or religious medium between the concrete and spirit worlds. 

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