pigheaded vs unsettled

pigheaded

adj
  • Obstinate and stubborn to the point of stupidity. 

unsettled

adj
  • Unpaid. 

  • Not populated, having no settlers or other inhabitants. 

  • Disturbed, upset. 

  • Not in a steady condition, uncertain, subject to change. 

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