agitation vs trepidation

agitation

noun
  • A disturbance of personal tranquillity; disturbance of someone's peace of mind. 

  • Excitement of public feeling by discussion, appeals, etc. 

  • The act of agitating, or the state of being agitated; the state of being disrupted with violence, or with irregular action; commotion. 

trepidation

noun
  • A fearful state; a state of concern or hesitation. 

  • An involuntary trembling, sometimes an effect of paralysis, but usually caused by terror or fear. 

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