harass vs overstrain

harass

verb
  • To put excessive burdens upon (someone); to subject (someone) to anxieties. 

  • To persistently bother (someone, or a group of people) physically or psychologically when such behaviour is illegal and/or unwanted, especially over an extended period. 

  • To annoy (someone) frequently or systematically; to pester. 

  • To trouble (someone, or a group of people) through repeated military-style attacks. 

overstrain

verb
  • To subject to an excessive demand on strength, resources, abilities, or the imagination. 

noun
  • excessive strain 

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