iniquity vs propriety

iniquity

noun
  • An act of great injustice or unfairness; a sinful or wicked act; an unconscionable deed. 

  • Deviation from what is right; gross injustice, sin, wickedness. 

propriety

noun
  • The fact of possessing something; ownership. 

  • Suitability, fitness; the quality of being appropriate. 

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

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