Continent vs Mainland

Continent

name

  • Mainland Europe, as seen from the British Isles. 

  • Synonym of Europe (including Britain) 

noun

  • An Encratite. 

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. 

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