frustration vs imperturbability

frustration

noun
  • A thing that frustrates. 

  • The feeling of annoyance at impassibility from resistance. 

  • The state of contract that allows a party to back away from its contractual obligations due to (unforeseen) radical changes to the nature of the thing a party has been obligated to. 

  • The act of frustrating, or the state, or an instance of being frustrated. 

  • Anger not directed at anything or anyone in particular. 

imperturbability

noun
  • A state of calm, unruffled self-assurance; aplomb, composure. 

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