iniquity vs wickedness

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. 

wickedness

noun
  • A wicked or sinful thing or act; morally bad or objectionable behaviour. 

  • The state of being wicked; evil disposition; immorality. 

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