nurse practitioner vs wet nurse

nurse practitioner

noun
  • A professional nursing designation recognized in some jurisdictions, denoting an individual who is fully qualified as a nurse and who has additional qualifications and authorization to provide diagnoses and/or treatments, including writing prescriptions . 

wet nurse

noun
  • Someone who treats someone else with excessive care. 

  • A woman hired to suckle another woman's child. 

verb
  • To act as a wet nurse (in either sense). 

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