incongruity vs polar opposite

incongruity

noun
  • A thing that is incongruous. 

  • The state of being incongruous, or lacking congruence. 

  • An instance or point of disagreement 

polar opposite

noun
  • The complete opposite, opposite in every way. 

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