politeness vs propriety

politeness

noun
  • The quality of being polite. 

  • An act of politeness. 

propriety

noun
  • Correctness in behaviour and morals; good manners, seemliness. 

  • The fact of possessing something; ownership. 

  • Suitability, fitness; the quality of being appropriate. 

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