mod con vs relevancy

mod con

noun
  • A modern convenience. 

relevancy

noun
  • A relevant thing. 

  • The degree to which a thing is relevant; relevance, applicability. 

  • Sufficiency (of a statement, claim etc.) to carry weight in law; legal pertinence. 

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