cleanness vs impropriety

cleanness

noun
  • The state of being physically clean and free of contamination or dirt; cleanliness. 

  • Moral purity; innocence. 

impropriety

noun
  • The condition of being improper. 

  • An improper act. 

  • Improper language. 

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