nouveau riche vs plutocrat

nouveau riche

noun
  • New money; wealthy persons whose fortunes are newly acquired, and who are therefore perceived to lack the refinement of those who were raised wealthy. 

adj
  • Newly rich; like a nouveau riche. 

plutocrat

noun
  • Someone who rules by virtue of his or her wealth. 

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