allowability vs properness

allowability

noun
  • The state of being allowable; legitimacy; permissibleness. 

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 allowability and properness occurred in a corpus of books? (source: Google Ngram Viewer )