bodyguard vs guardian angel

bodyguard

noun
  • A person or group of persons, often armed, responsible for protecting an individual. 

verb
  • To act as bodyguard for (someone); figuratively, to protect. 

guardian angel

noun
  • A tutelary angel watching over a particular person in monotheistic contexts. 

  • A person who watches over another. 

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