pail vs shipping container

pail

noun
  • A closed (covered) cylindrical shipping container. 

  • 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). 

shipping container

noun
  • A standardized reusable steel box used for the storage and transportation of materials and products within a freight transport system. 

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