kick a dog when it's down vs twist the knife

kick a dog when it's down

verb
  • To make things worse for someone in an adverse situation. 

twist the knife

verb
  • To deliberately do or say something to worsen a difficult situation or increase a person's distress, irritation, or anger. 

How often have the words kick a dog when it's down and twist the knife occurred in a corpus of books? (source: Google Ngram Viewer )