awfulness vs dreadfulness

awfulness

noun
  • The state or quality of being awful. 

  • the awfulness of this sacred place 

  • The state of being struck with awe; a spirit of solemnity; profound reverence. 

  • The quality of striking with awe, or with reverence 

dreadfulness

noun
  • The characteristic of being dreadful. 

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