caretaker vs registered nurse

caretaker

noun
  • Someone who takes care of a person; a parent, carer or other guardian. 

  • Someone who takes care of a place or thing; someone looking after a place, or responsible for keeping it in good repair. 

adj
  • Temporary, on a short term basis. 

registered nurse

noun
  • A professional nurse who is a licensed graduate of a university or college of nursing who has successfully passed an examination such as NCLEX-RN. 

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