charade vs sixty-four dollar question

charade

verb
  • To act out a charade (of); to gesture; to pretend. 

noun
  • A deception or pretense, originally an absurdly obvious one but now in general use. 

  • A single round of the game charades, an acted form of the earlier riddles. 

sixty-four dollar question

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