nomadic vs on foot

nomadic

adj
  • Of or related to any habitually wandering person or animal. 

  • Of or related to itinerant herdsmen. 

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. 

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