highwayman vs rustler

highwayman

noun
  • A person, usually mounted on horseback, who robbed travelers on public roads. 

rustler

noun
  • One who rustles; a cattle (or other livestock) thief. 

  • A bovine animal that can care for itself in any circumstances. 

  • That which makes a rustling noise. 

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