oligarch vs shah

oligarch

noun
  • A very wealthy business owner who wields political power. 

  • A member of an oligarchy; someone who is part of a small group that runs a country. 

  • A protoplanet formed during oligarchic accretion. 

shah

noun
  • A supreme ruler in some Middle Eastern or South Asian nations. 

  • A king of Persia or Iran. 

  • A Ukrainian monetary unit. 

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