intelligibility vs simplicity

intelligibility

noun
  • That which is intelligible; the degree to which something is intelligible. 

  • The quality of recorded speech of every word being understandable. 

simplicity

noun
  • Lack of subtlety or abstruseness; clarity 

  • Lack of artificial ornament, pretentious style, or luxury; plainness 

  • Lack of complication; efficiency. 

  • The quality or state of being not complex, or of consisting of few parts 

  • The quality or state of being unmixed or uncompounded 

  • Lack of sharpness of mind; lack of ability to think using complex ideas; stupidity 

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