Scot vs Scotchman

Scot

noun
  • A person born in or native to Scotland. 

name
  • A male given name transferred from the surname, of rare usage, variant of Scott. 

Scotchman

name
  • A surname. 

noun
  • A piece of wood or stiff hide placed over shrouds and other rigging to prevent chafe by the running gear. 

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