ACW vs anticlockwise

ACW

anticlockwise

adj
  • in a circular fashion so as to be moving to the left at the top of the circle and to the right at the bottom (when viewed from the front), in the opposite direction to the way the hands of an analogue clock move. 

adv
  • In an anticlockwise fashion. 

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