injustice vs tyranny

injustice

noun
  • Violation of the rights of another person or people. 

  • Absence of justice; unjustice. 

  • Unfairness; the state of not being fair or just. 

tyranny

noun
  • The office or jurisdiction of an absolute ruler. 

  • A government in which a single ruler (a tyrant) has absolute power; this system of government. 

  • Extreme severity or rigour. 

  • Absolute power, or its use. 

  • A system of government in which power is exercised on behalf of the ruler or ruling class, without regard to the wishes of the governed. 

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