caught on the hop vs stunned

caught on the hop

adj
  • In a situation for which one is unprepared. 

  • In a situation of change, especially from a known to an unknown state. 

stunned

adj
  • Unable to act or respond; dazed; shocked. 

How often have the words caught on the hop and stunned occurred in a corpus of books? (source: Google Ngram Viewer )