disquiet vs pester

disquiet

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

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

pester

verb
  • To bother, harass, or annoy persistently. 

noun
  • A bother or nuisance. 

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