snail's pace vs straggle

snail's pace

noun
  • A very slow pace. 

straggle

noun
  • An outlier; something that has strayed beyond the normal limits. 

  • An irregular, spread-out group. 

verb
  • To act in a disorderly and irregular way 

  • To stray, rove, or wander from a normal course and others of its kind. 

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