permissibility vs properness

permissibility

noun
  • The condition of being permissible; legitimacy; allowability. 

  • A permissible act. 

properness

noun
  • The state or condition of being proper; propriety. 

  • The state or condition of being proper (of a proper fraction, proper subset, etc.). 

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