Question: Since when has Clive Schlee been CEO of an  international sandwich shop chain?

Context articles: Burger King fish sandwiches
Clive Schlee
Defonte's
Stop &amp; Shop/Giant-Landover
Sub Station II
Brocato's Sandwich Shop
Quiznos
Pret a Manger
Duckfat
Wilson's Sandwich Shop

International fast-food restaurant chain Burger King and its Australian franchise Hungry Jack's have had a variety of fish sandwiches in their product portfolio since 1975.
 The Whaler sandwich was the first iteration, designed to compete with rival burger-chain McDonald's Filet-O-Fish sandwich.
 With the addition of the company's Specialty Sandwich line in 1978, the sandwich was reformulated as the Long Fish sandwich.
 With the discontinuation of the Specialty Sandwich line, the sandwich was returned to its original recipe and name.
 With the introduction of the company's BK Broiler chicken sandwich in 1990, the fish sandwich became tied to the development cycle of the broiled chicken sandwich and was again reformulated and renamed as the Ocean Catch Fish fillet.
 When the broiled chicken sandwich underwent another reformulation in 2002, the fish sandwich was also redone and renamed as the BK Big Fish sandwich.
 By 2015, the sandwich had undergone several more modifications and went through a series of names including the BK Fish and Premium Alaskan fish sandwich.
 It is currently sold as the BK Big Fish sandwich in the United States and Canada.
 Internationally the fish sandwich is also known as the BK Fish, BK Fish'n Crisp burger and Fish Royale in those markets.
Clive Edward Benedict Schlee (born March 1959) is a British businessman, the CEO of the UK fast food chain Pret a Manger since 2003.
 He is related to several companies, e. g. ITSU Limited, Action Rock Limited, Shire Cape Limited.
Defonte's is a sandwich shop in the Red Hook, Brooklyn, New York City.
 It is known for large Italian heroes with ham, provolone, salami, roast beef, mozzarella and fried eggplant.
 There is also a steak pizzaiola sandwich.
 The eatery was featured on "Diners, Drive-Ins and Dives" on February 20, 2012 in the Long Standing Legacies episode.
Stop & Shop/Giant-Landover was a combined supermarket chain owned by the American subsidiary of the Dutch retailer Ahold.
 The company took its form in 2004, after Ahold decided to combine the operations of its New England-based Stop & Shop chain with its DMV-based Giant Food chain to create the largest supermarket company in the Mid-Atlantic States.
 Giant's headquarters relocated in Landover, Maryland, and Stop & Shop kept their headquarters in Quincy, Massachusetts.
 This combination failed, as Mid-Atlantic market area shoppers grocery needs did not align with those of Stop & Shop's offerings.
 In 2011 the two companies were separated and now operate independently.
 The separation of Stop & Shop/Giant-Landover, also brought the separation of the Stop & Shop Supermarket into two separate operating divisions, Stop & Shop-New England and Stop & Shop-New York.
 Both Giant Food and Stop & Shop's two divisions continue to share the same Fruit Basket Logo even though they all operate independently.
Sub Station II is a small sandwich shop chain started in Sumter, South Carolina by three brothers, Don, John and Charlie Ruffalo.
 Their original unit, The Sub Station, opened in May 1975.
Brocato's Sandwich Shop is a historic eatery in Tampa, Florida.
 It opened in 1948 is located on Columbus Drive (Tampa).
 Offerings include a Cuban sandwich.
 Brocato's is "widely regarded as one of Tampa's landmark eateries."
QIP Holder, LLC, doing business as Quiznos, is a franchised fast-food restaurant brand based in Denver, Colorado that specializes in offering toasted submarine sandwiches.
 It was founded in 1981 by Jimmy Lambatos and sold to Rick and Richard Schaden ten years later, before growing to nearly 5,000 restaurants afterwards.
 As of late-2013, the chain had about 1,500 domestic locations and about 600 international locations.
 Quiznos is the second-largest submarine sandwich shop chain in North America, behind Subway.
Pret a Manger is an international sandwich shop chain based in the United Kingdom, commonly referred to simply as "Pret".
Duckfat is a small restaurant and alternative sandwich shop in Portland, Maine.
 Located at 143 Middle Street in the Old Port neighborhood, the restaurant was opened in 2005 by Rob Evans, a local chef.
 Evans also owns a nearby restaurant named "Hugo's".
 The name derives from the main menu item, Belgian french fries twice cooked in duckfat.
 In 2004, the restaurant's tuna melt sandwich was named one of the top sandwiches in the United States by Esquire Magazine.
Wilson's Sandwich Shop is a spin-off business of the Kewpee Hamburger chain located in Findlay, OH.