nonpositive vs unclean

nonpositive

adj
  • Not positive. 

  • Not positive; either zero or negative. 

noun
  • Any value that is not positive. 

unclean

adj
  • Not moral or chaste. 

  • Dirty, soiled or foul. 

  • Ritually or ceremonially impure or unfit. 

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