metropole vs urheimat

metropole

noun
  • The parent-state of a colony. 

  • A metropolis; the main city of a country or area. 

urheimat

noun
  • The original homeland of an ethnic group, particularly the speakers of a proto-language; the cradleland. 

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