flash in the pan vs mishap

flash in the pan

noun
  • A career notable for early success not followed by significant accomplishment. 

  • A transient occurrence with no long-term effect. 

mishap

noun
  • An accident, mistake, or problem. 

  • Evil accident; ill luck; misfortune; mischance. 

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