cautionary vs unlucky

cautionary

adj
  • Serving to caution or warn; admonitory 

  • Serving to ward off; preventive 

unlucky

adj
  • Unfortunate, marked by misfortune. 

  • Having ill luck. 

  • Inauspicious. 

  • Bringing ill luck. 

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