disquiet vs unsettle

disquiet

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

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

unsettle

verb
  • To make upset or uncomfortable 

  • To bring into disorder or disarray 

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