take flight vs take off

take flight

verb
  • To begin flying; to become airborne or aloft; to take off and fly 

  • to flee 

take off

verb
  • To leave the ground and begin flight; to ascend into the air. 

  • To depart. 

  • To absent oneself from (work or other responsibility), especially with permission. 

  • To quantify. 

  • To remove. 

  • To imitate, often in a satirical manner. 

  • To become successful, to flourish. 

How often have the words take flight and take off occurred in a corpus of books? (source: Google Ngram Viewer )