The market size of the domestic restaurant industry is about 25 trillion yen. The Skylark Group owns more than 20 brands to meet customers' ever-changing needs.
Our wide portfolio of brands can be found in the approximately 3,200 stores in Japan and Taiwan. The Skylark Group serves an annual average of 400 million customers.
Approximately 100,000 staff members work at the Skylark Group's stores across Japan. Around 35 % of them have been with the Group for more than 3 years.
A retention rate that is better than the industry average is one of the factors that help us provide quality service to our customers.
The Skylark group is actively investing in stores, and has implemented remodeling (renovations of interior and exterior on approx. 1,500 stores), brand conversion (approx. 300 stores) and new openings (approx. 270 stores) for more than 2,000 stores in the last five years. We continue to improve customer satisfaction by responding to changing markets and providing comfortable store environment.
The total number of plates served by the Skylark Group's wide variety of brands is approximately 2,400. We use more than 3,000 ingredients to prepare these menus. Foodstuffs are primary processed at 10 locations of central kitchen nationwide, to enhance efficiency of cooking at the restaurants. Taking hamburger as an example, we offer 75 million patties per year to our customers.
Also, in order for customers to enjoy our delicious dishes at reasonable price even at home, we provide delivery service at about 1,000 stores as well as focus on take-out service.
We conduct regular hygiene inspections in our stores and provide detailed instructions about how to manage food and how to clean up. Bacteria tests are conducted every day-365 days a year. The items to be checked in the bacteria test, the average level, and the test frequency are specified per item. We have about 170 evaluation standards, and test as many as 130,000 samples a year, which is more than any other competitor in the industry.
In addition, our staff members make it a rule to wash their hands twice, using soap and antiseptic, for 100 seconds both before starting work and after going to the restroom.