danger vs opportunity

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. 

opportunity

noun
  • A favorable circumstance or occasion. 

  • opportuneness 

  • A chance for advancement, progress or profit. 

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