famulus vs houseboy

famulus

noun
  • A close attendant or assistant, especially of a magician or occult scholar. 

houseboy

noun
  • A non-white adult male domestic servant. 

  • A young male domestic servant, especially in a British colony in former times. 

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