on foot vs unsettled

on foot

prep
  • In progress or in preparation; active, in operation. 

  • On one's feet; walking, jogging or running but not in a vehicle or on the back of an animal. 

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 on foot and unsettled occurred in a corpus of books? (source: Google Ngram Viewer )