impaired vs nonpositive

impaired

adj

  • Rendered less effective. 

  • inebriated, drunk. 

noun

  • A criminal charge for driving a vehicle while impaired. 

nonpositive

adj

  • Not positive. 

  • Not positive; either zero or negative. 

noun

  • Any value that is not positive. 

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