chantage vs exaction

chantage

noun
  • blackmail; the extortion of money by threats of scandalous revelations 

exaction

noun
  • extortion. 

  • The act of demanding with authority, and compelling to pay or yield; compulsion to give or furnish; a levying by force 

  • That which is exacted; a severe tribute; a fee, reward, or contribution, demanded or levied with severity or injustice. 

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