nonpositive vs poisonous

nonpositive

adj

  • Not positive. 

  • Not positive; either zero or negative. 

noun

  • Any value that is not positive. 

poisonous

adj

  • Negative, harmful. 

  • Containing sufficient poison to be dangerous to touch or ingest. 

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