Cassandra vs voice of doom

Cassandra

name
  • A female given name from Ancient Greek. 

  • An unincorporated community in Walker County, Georgia, United States. 

  • A prophetess who was daughter of King Priam of Troy and his queen Hecuba. She captured the eye of Apollo and was granted the ability to see the future; however, she was destined never to be believed. 

  • A small borough in Cambria County, Pennsylvania, United States. 

noun
  • A person who makes dire predictions, especially those which are not believed but which turn out to be true. 

voice of doom

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