relevancy vs unsuitability

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. 

unsuitability

noun
  • The quality of being unsuitable. 

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