parka vs winter coat

parka

noun
  • A long jacket with a hood which protects the wearer against rain and wind. 

winter coat

noun
  • A warm coat, often an overcoat, fit to be worn in winter 

  • An animal's seasonal appearance in winter, notably thicker and/or otherwise camouflaged plumage or fur after (often autumnal) moulting 

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