ethnic cleansing vs frankpledge

ethnic cleansing

noun
  • The mass expulsion or killing of people belonging to one ethnic group by those of another. 

frankpledge

noun
  • Any group so similarly answerable for the conduct of all its members and liable for collective punishment. 

  • A decener: a member of a tithing bound in frankpledge. 

  • The tithing itself. 

  • A form of collective suretyship and punishment under English law among the members of a tithing. 

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