disturb vs pester

disturb

verb
  • to divert, redirect, or alter by disturbing. 

  • to confuse a quiet, constant state or a calm, continuous flow, in particular: thoughts, actions or liquids. 

  • to have a negative emotional impact; to cause emotional distress or confusion. 

pester

verb
  • To bother, harass, or annoy persistently. 

noun
  • A bother or nuisance. 

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