snail's pace vs zigzag

snail's pace

noun
  • A very slow pace. 

zigzag

noun
  • A line or path that proceeds by sharp turns in alternating directions. 

  • One of these sharp turns. 

adv
  • in a zigzag manner or pattern 

adj
  • Moving in, or having a zigzag. 

verb
  • To move or to twist in a zigzag manner. 

How often have the words snail's pace and zigzag occurred in a corpus of books? (source: Google Ngram Viewer )