fake news vs figment of one's imagination

fake news

noun
  • Satirical news stories, intended to amuse. 

  • News stories with false or misleading information, deliberately created to disinform. 

figment of one's imagination

noun
  • A product of the imagination. 

How often have the words fake news and figment of one's imagination occurred in a corpus of books? (source: Google Ngram Viewer )