danger vs heroism

danger

noun
  • An instance or cause of likely harm. 

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

  • Exposure to likely harm; peril. 

heroism

noun
  • The qualities characteristic of a hero, such as courage, bravery, fortitude, selflessness, etc.; the display of such qualities. 

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