Mainland vs Palatinate

Mainland

name
  • A historical region in British Columbia, British North America, British Empire 

  • The largest island in the Orkney Islands council area, to the north of Scotland. 

  • The largest island in the Shetland Islands council area, to the north of both Orkney and Scotland. 

Palatinate

name
  • Any of various historical counties palatinate 

  • The County Palatinate of the Rhine or Electoral Palatinate of the Holy Roman Empire. 

  • The area of the former German County Palatinate as a region of modern Germany. 

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