cavil vs pester

cavil

noun
  • A petty or trivial objection or criticism. 

verb
  • To criticise for petty or frivolous reasons. 

pester

noun
  • A bother or nuisance. 

verb
  • To bother, harass, or annoy persistently. 

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