irenic vs propitiative

irenic

adj
  • Promoting or fitted to promote peace, especially over disputes; conciliatory, non-confrontational, peaceful. 

propitiative

adj
  • Serving to, or intended to, propitiate; propitiatory, reconciliatory 

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