clarity vs perspicuousness

clarity

noun
  • The state or measure of being clear, either in appearance, thought or style; lucidity. 

  • The ability to be easily understood. 

perspicuousness

noun
  • The state or characteristic of being perspicuous; perspicuity. 

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