housekeeper vs practical nurse

housekeeper

noun
  • Someone (traditionally a woman) employed to look after the home, typically by managing domestic servants or superintending household management; also someone with equivalent duties in a hotel, institution etc. 

  • Someone who manages the running of a home, traditionally the female head of the household. 

practical nurse

noun
  • A person who is certified to provide custodial care such as help in walking, bathing, and feeding. 

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