flea market vs yard sale

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  • A permanent indoor market of stalls in a warehouse selling inexpensive antiques, outdated goods, curios, etc. 

yard sale

noun
  • A sale of used household goods held on the seller's own premises. 

  • The state that the participant (skier, snowboarder, skateboarder, cyclist, etc.) and their equipment is in after a nasty crash, whereupon they and their equipment is laid out across the ground like pieces of a yard sale. 

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