ghoulish vs unnatural

ghoulish

adj
  • Of or pertaining to ghouls. 

  • Of or pertaining to corpses and graverobbing. 

  • Fascinated by corpses. 

unnatural

adj
  • Going against nature; perverse. 

  • Not occurring in nature, the environment or atmosphere 

  • Not natural. 

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