McDonald's is the largest chain of hamburger fast food restaurants in the world. It operates restaurants through franchises, affiliates, or directly. McDonald's income comes from rent, royalties and fees from franchisees as well as company-operated restaurant sales, which grew 27% over three years to $22.8 billion. McDonald's sells hamburgers, chicken, fries, drinks and breakfast items, and has added healthier options like salads and wraps. It began in 1940 in California and introduced principles of fast food like efficiency that are still used today. Characteristics of McDonald's in East Asia include only selling chicken in India for religious reasons and using bike delivery in South Korea and Thailand.