megastore vs milk bar

megastore

noun
  • A large supermarket or similar retail outlet; a superstore. 

milk bar

noun
  • A convenience store. 

  • A small shop and/or cafe, often part of a larger shop, that sells fast food and a range of dairy based beverages such as milkshakes and ice creams; a deli or delicatessen. 

How often have the words megastore and milk bar occurred in a corpus of books? (source: Google Ngram Viewer )