exchange of contracts vs sale

exchange of contracts

noun
  • The act of exchanging contracts. 

  • The point or stage at which a conveyancing contract comes into existence between negotiating parties for the carrying out of a disposition of an estate in land; usually requiring the payment of a deposit. 

sale

noun
  • An exchange of goods or services for currency or credit. 

  • The act of putting up for auction to the highest bidder. 

  • The sale of goods at reduced prices. 

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