danger vs instability

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. 

instability

noun
  • The quality of being unstable. 

  • A state that is not in equilibrium, or in which a small change has a large irreversible effect. 

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