nonnegotiable vs nontransferable

nonnegotiable

adj

  • Not negotiable; not subject to negotiation. 

noun

  • Something that is not negotiable. 

nontransferable

adj

  • Not transferable; not able to be transferred. 

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