democracy vs oligarchy

democracy

noun
  • Rule by the people, especially as a form of government; either directly or through elected representatives (representative democracy). 

  • A government under the direct or representative rule of the people of its jurisdiction. 

  • Belief in political freedom and equality; the "spirit of democracy". 

  • A state with a democratic system of government. 

oligarchy

noun
  • Those who make up an oligarchic government. 

  • A state ruled by such a government. 

  • A government run by only a few, often the wealthy. 

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