backflip vs frontflip

backflip

noun
  • An act of rotating one's body 360 degrees in the backward direction. 

  • a total reversal in policy or opinion; a volte-face, a U-turn. 

verb
  • To perform a backflip (rotation of body). 

  • To completely reverse a policy or opinion; perform a U-turn. 

frontflip

noun
  • A floor movement, consisting of rotating one's body in the air 360 degrees in the forward direction. 

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