cadet vs stable boy

cadet

noun
  • A young gentleman learning sheep farming at a station; also, any young man attached to a sheep station. 

  • Junior. (See also the heraldic term cadency.) 

  • A younger or youngest son, who would not inherit as a firstborn son would. 

  • A participant in a cadetship. 

  • A student at a military school who is training to be an officer. 

stable boy

noun
  • A boy or young man who attends in a stable. 

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