flea market vs strip mall

flea market

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  • A permanent indoor market of stalls in a warehouse selling inexpensive antiques, outdated goods, curios, etc. 

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

strip mall

noun
  • A shopping center consisting of a row of stores with separate entrances from the outdoors, typically along a road and/or with a parking lot in front. 

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