aptness vs incongruity

aptness

noun
  • disposition of the mind; propensity 

  • suitability; the quality of being apt or suitable 

  • speed or readiness in learning; docility 

  • proneness; tendency 

incongruity

noun
  • A thing that is incongruous. 

  • The state of being incongruous, or lacking congruence. 

  • An instance or point of disagreement 

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