CG vs c.g.

CG

noun
  • in a visual novel: a unique, static full-screen image, usually displayed to illustrate a significant event in the story. 

  • cover girl 

  • coast guard 

  • guided missile cruiser 

  • the statistic reporting the number of "Complete Games" thrown by a pitcher 

c.g.

How often have the words CG and c.g. occurred in a corpus of books? (source: Google Ngram Viewer )