aft vs back to front

aft

adj

  • located at the back of a boat, ship, or airplane 

adv

  • At, near, or towards the stern of a vessel (with the frame of reference within the vessel). 

noun

  • The stern portion of a vessel. 

back to front

adj

  • Reversed, with the back now at the front. 

adv

  • Turned so that the back is now at the front. 

How often have the words aft and back to front occurred in a corpus of books? (source: Google Ngram Viewer )