confident vs promissory

confident

adj
  • Self-assured, self-reliant, sure of oneself. 

  • Very sure of something; positive. 

promissory

adj
  • Containing or consisting of a promise. 

  • Stipulating the future actions required of the parties to an insurance policy or other business agreement. 

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