discount store vs flea market

discount store

noun
  • A type of department store which sell products at prices lower than those asked by other department stores. 

flea market

noun
  • An outdoor temporary market selling inexpensive antiques, curios etc. 

  • A permanent indoor market of stalls in a warehouse selling inexpensive antiques, outdated goods, curios, etc. 

How often have the words discount store and flea market occurred in a corpus of books? (source: Google Ngram Viewer )