charity shop vs flea market

charity shop

noun
  • A shop to where goods are donated, and sold on at cheap prices, with all the profits going to charity 

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  • A permanent indoor market of stalls in a warehouse selling inexpensive antiques, outdated goods, curios, etc.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 charity shop and flea market occurred in a corpus of books? (source: Google Ngram Viewer )