maze vs sixty-four dollar question

maze

noun
  • Something made up of many confused or conflicting elements; a tangle. 

  • A labyrinth; a puzzle consisting of a complicated network of paths or passages, the aim of which is to find one's way through. 

sixty-four dollar question

How often have the words maze and sixty-four dollar question occurred in a corpus of books? (source: Google Ngram Viewer )