disquiet vs trepidation

disquiet

noun
  • Lack of quiet; absence of tranquility in body or mind 

verb
  • To make (someone or something) worried or anxious. 

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 disquiet and trepidation occurred in a corpus of books? (source: Google Ngram Viewer )