casket vs packing case

casket

noun
  • A little box, e.g. for jewellery. 

  • A gasket. 

  • An urn. 

  • A coffin. 

verb
  • To put into, or preserve in, a casket. 

packing case

noun
  • A large, sturdy box or wooden crate used for the secure shipment of goods. 

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