nonnegative vs satisfactory

nonnegative

noun
  • Any value that is not negative. 

satisfactory

noun
  • The rating given to somebody or something that meets requirements without exceeding them. 

  • Somebody or something that meets requirements without exceeding them. 

adj
  • Causing satisfaction; agreeable or pleasant; satisfying. 

  • Done to satisfaction; adequate or sufficient. 

  • Making atonement for a sin; expiatory. 

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