blackout vs persistent vegetative state

blackout

noun
  • A temporary loss of consciousness. 

  • The blocking out of as much light as possible. 

  • A large-scale power failure, and resulting loss of electricity to consumers. 

  • A temporary loss of memory. 

  • The mandatory blocking of all light emanating from buildings, as well as outdoor and street lighting as a measure against aerial bombing or naval attack, as imposed during, e.g., World War II. 

  • An instance of censorship, especially a temporary one. 

persistent vegetative state

noun
  • A condition of patients with severe brain damage in whom coma has progressed to a state of wakefulness without awareness. 

How often have the words blackout and persistent vegetative state occurred in a corpus of books? (source: Google Ngram Viewer )