hostler vs stableman

hostler

noun
  • A person employed at an inn, hostelry, or stable to look after horses; a groom 

  • A person employed to care for a locomotive or other large engine. 

stableman

noun
  • A person employed to take care of horses in a stable. 

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