danger vs dangerousness

danger

noun
  • Exposure to likely harm; peril. 

  • An instance or cause of likely harm. 

  • The stop indication of a signal (usually in the phrase "at danger"). 

dangerousness

noun
  • The state or quality of being dangerous. 

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