pail vs waterjug

pail

noun
  • A vessel of wood, tin, plastic, etc., usually cylindrical and having a handle -- used especially for carrying liquids, for example water or milk; a bucket (sometimes with a cover). 

  • A closed (covered) cylindrical shipping container. 

waterjug

noun
  • A jug used to hold water. 

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