flee vs whistle in the wind

flee

verb
  • To disappear quickly; to vanish. 

  • To run away; to escape. 

  • To escape from. 

whistle in the wind

verb
  • To attempt something that is futile; to say something that is not heeded. 

How often have the words flee and whistle in the wind occurred in a corpus of books? (source: Google Ngram Viewer )