displaced person vs wanderer

displaced person

noun
  • A refugee, especially of war or of forced migration. 

wanderer

noun
  • One who wanders, who travels aimlessly. 

  • Any of various far-migrating nymphalid butterflies of the genus Danaus. 

  • The wandering albatross, Diomedea exulans. 

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