RN vs caretaker

RN

caretaker

adj
  • Temporary, on a short term basis. 

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. 

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