nonpositive vs unmitigable

nonpositive

adj

  • Not positive. 

  • Not positive; either zero or negative. 

noun

  • Any value that is not positive. 

unmitigable

adj

  • Not able to be mitigated or made less severe; not mitigable. 

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