snail's pace vs wag

snail's pace

noun
  • A very slow pace. 

wag

noun
  • An oscillating movement. 

  • A witty person. 

verb
  • To swing from side to side, such as of an animal's tail, or someone's head, to express disagreement or disbelief. 

  • To play truant from school. 

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