on foot vs ranging

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. 

ranging

noun
  • A back-and-forth movement. 

  • The act of one who ranges. 

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