oligarch vs tycoon

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. 

tycoon

noun
  • A wealthy and powerful business person. 

  • A type of Roblox game in which players earn money which is then used to purchase upgrades. 

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