inefficacious vs nonpositive

inefficacious

adj
  • Not effective. 

  • Incapable of having the intended consequence. 

nonpositive

adj
  • Not positive. 

  • Not positive; either zero or negative. 

noun
  • Any value that is not positive. 

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