panic-stricken vs unflappable

panic-stricken

adj
  • Very frightened, and unable to react sensibly because of panic. 

unflappable

adj
  • Remaining composed and level-headed at all times; impossible to fluster; not becoming frustrated or irritated easily. 

How often have the words panic-stricken and unflappable occurred in a corpus of books? (source: Google Ngram Viewer )