supermarket vs trading post

supermarket

noun
  • A chain of such stores. 

  • A one-stop shop; a place offering a range of products or services. 

  • A large self-service store that sells groceries and, usually, medications, household goods, and/or clothing. 

trading post

noun
  • A place where trading of goods takes place. 

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