make off vs show a clean pair of heels

make off

verb
  • To exit or depart; to run away. 

  • To tie off, fix down or terminate the end of a rope, cable or thread. 

show a clean pair of heels

verb
  • To run away; to make an escape quickly. 

How often have the words make off and show a clean pair of heels occurred in a corpus of books? (source: Google Ngram Viewer )