zag vs zig

zag

noun
  • One of a series of sharp turns or reversals. 

  • twist in a storyline 

verb
  • To move with a sharp turn or reversal. 

zig

noun
  • A sudden or sharp turn or change of direction. 

verb
  • To make such a turn. 

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