houseboy vs slavey

houseboy

noun
  • A non-white adult male domestic servant. 

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

slavey

noun
  • A male servant. 

  • A female domestic servant; a maid or maidservant. 

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