flunkey vs houseboy

flunkey

noun
  • An underling; a liveried servant or a footman; servant, retainer – a person working in the service of another (especially in the household). 

  • One easily deceived in buying stocks; an inexperienced and unwary jobber. 

  • One who is obsequious or cringing; a snob. 

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 flunkey and houseboy occurred in a corpus of books? (source: Google Ngram Viewer )