angst vs heroism

angst

verb
  • To suffer angst; to fret. 

noun
  • Emotional turmoil; painful sadness. 

  • A feeling of acute but vague anxiety or apprehension often accompanied by depression, especially philosophical anxiety. 

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 angst and heroism occurred in a corpus of books? (source: Google Ngram Viewer )