clan vs sept

clan

noun
  • A traditional social group of families in the Scottish Highlands having a common hereditary chieftain 

  • Any group defined by family ties with some sort of political unity. 

  • A group of players who habitually play on the same team in multiplayer games. 

  • A badger colony. 

  • A group of people all descended from a common ancestor, in fact or belief, especially when the exact genealogies are not known. 

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 clan and sept occurred in a corpus of books? (source: Google Ngram Viewer )