electrocution vs lethal injection

electrocution

noun
  • The accidental death or suicide by electric shock. 

  • A severe electric shock, whether fatal or not. 

  • Deliberate execution by electric shock, usually involving an electric chair. 

lethal injection

noun
  • A means of execution or of euthanasia in which a person is injected with a fatal dose of drugs. 

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