healer vs medical practitioner

healer

noun
  • One who heals, especially through faith. 

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

medical practitioner

noun
  • A person who practices medicine, especially one licensed to do so, such as a physician, dentist, surgeon, or veterinarian. 

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