cautionary vs warning

cautionary

adj
  • Serving to caution or warn; admonitory 

  • Serving to ward off; preventive 

warning

noun
  • Something spoken or written that is intended to warn. 

  • The action of the verb warn; an instance of warning someone. 

intj
  • Used to warn of danger in signs and notices. 

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