ethnos vs sept

ethnos

noun
  • An ethnic group, or a people who have a common national or cultural tradition 

sept

noun
  • A clan, tribe, or family, proceeding from a common progenitor; especially, one of the ancient clans of Ireland. 

  • An enclosure; a railing. 

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