autocracy vs quinquevirate

autocracy

noun
  • An instance of this government. 

  • A form of government in which unlimited power is held by a single individual. 

quinquevirate

noun
  • An official group of five people, especially a council of five men sharing office or rule. 

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