nervous vs unperturbed

nervous

adj
  • Affecting the nerves or nervous system. 

  • Easily agitated or alarmed; edgy, on edge. 

  • Apprehensive, anxious, hesitant, worried. 

  • Supplied with nerves; innervated. 

unperturbed

adj
  • Not perturbed 

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