expository vs ratiocinative

expository

adj
  • Serving to explain, explicate, or elucidate; expositive; of or relating to exposition. 

ratiocinative

adj
  • Pertaining to or characterized by ratiocination, discursive thinking, or inferential knowledge. 

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