favourable vs nonnegative

favourable

noun
  • A favourable person 

adj
  • Pleasing, encouraging or approving. 

  • Useful or helpful. 

  • Auspicious or lucky. 

  • Convenient or at a suitable time; opportune. 

nonnegative

noun
  • Any value that is not negative. 

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