Question: What is the  2015 estimated wealth of Franklin Clarence Mars, founder of Mars, Incorporated?

full_context: Document 1: Mars Nederland: Mars Nederland (English: Mars Netherlands ) is the Dutch division of Mars, Incorporated, a privately held multi-national company in food, pet care products, and confectionery products. It has its headquarters and main production site in Veghel, North Brabant. A second production site is located in Oud-Beijerland, South Holland. The chocolate factory in Veghel is the largest production site owned by Mars, Incorporated, and is among the largest chocolate factories in the world.
Document 2: Franklin Clarence Mars: Franklin Clarence Mars ( ; September 24, 1882 – April 8, 1934), sometimes known as Frank C. Mars, was an American business magnate who founded the food company Mars, Incorporated, which mostly makes chocolate candy. Mars' son Forrest Edward Mars developed M&M's and the Mars bar.
Document 3: Pietro Ferrero: Pietro Ferrero (2 September 1898 – 2 March 1949) was the founder of Ferrero SpA, an Italian confectionery and chocolatier company. His company invented Nutella, a hazelnut-cream spread, which is now sold in over 160 countries. The famous Ferrero Rochers are also made by his company, Ferrero, as were Tic-Tacs and various Kinder chocolates.
Document 4: Milka: Milka is a brand of chocolate confection which originated in Switzerland in 1901 and has been manufactured internationally by the US confectionery company Mondelēz International (formerly known as Kraft Foods) since 1990. For more than 100 years Milka has been primarily produced in Lörrach, Germany, producing about 140,000 tonnes of chocolate in 2012. It is sold in bars and a number of novelty shapes for Easter and Christmas. Milka also produces chocolate-covered cookies and biscuits.
Document 5: Walter Baker &amp; Company: The Baker Chocolate Company is the oldest producer of chocolate in the United States. The company was established when a physician named Dr. James Baker met John Hannon on the banks of the Neponset River. Irishman John Hannon was penniless but was a skilled chocolatier, a craft which he had learned in England and which was, until now, exclusive to Europe. With the help of Baker, Hannon was able to set up a business where he produced “Hannon’s Best Chocolate” for 15 years. In 1779, Hannon went on a trip to the West Indies and never returned. His wife sold the company in 1780 to Dr. Baker who changed the name to Baker Chocolate Company. The Baker's Chocolate brand now belongs to Mondelez International.
Document 6: 3 Musketeers (chocolate bar): 3 Musketeers is a candy bar made in the United States and Canada by Mars, Incorporated. It is a chocolate-covered fluffy whipped chocolate bar. The 3 Musketeers Bar was the third brand produced and manufactured by M&M/Mars, introduced in 1932. Originally, it had three pieces in one package, flavored chocolate, strawberry and vanilla; hence the name, which was derived from the novel "The Three Musketeers". Rising costs and wartime restrictions on sugar saw the phasing out of the vanilla and strawberry pieces to leave only the more popular chocolate. Costing five cents when it was introduced, it was marketed as one of the largest chocolate bars available, one that could be shared by friends.
Document 7: Ethel V. Mars: Ethel Veronica Mars (1884 – December 25, 1945) was an American businesswoman and racehorse owner. She was Ethel Veronica Healy prior to her marriage in 1910 to Franklin Clarence Mars, the founder of the Mars Candy company.
Document 8: Ferrero SpA: Ferrero SpA (] ) is an Italian manufacturer of branded chocolate and confectionery products and it is the third biggest chocolate producer and confectionery company in the world. It was founded in 1946 in Alba, Piedmont, Italy, by Pietro Ferrero, a confectioner and small-time pastry maker who laid the groundwork for Nutella and famously added hazelnut to save money on chocolate. The company saw a period of tremendous growth and success under Pietro's son Michele Ferrero, who in turn handed over the daily operations to his sons. His son Pietro (the founder's grandson), who oversaw global business, died on April 18, 2011, in a cycling accident in South Africa at the age of 47. The Ferrero Group worldwide – now headed by CEO Giovanni Ferrero – includes 38 trading companies, 18 factories, approximately 21,500 employees and produces around 365,000 tonnes of Nutella each year. Ferrero International SA's headquarters is in Luxembourg. Ferrero SpA is a private company owned by the Ferrero family and has been described as "one of the world's most secretive firms". Reputation Institute's 2009 survey ranks Ferrero as the most reputable company in the world. The recently announced financial results for the fiscal year ending August 31, 2016 showed consolidated sales growth of 8.2% from the previous fiscal year.
Document 9: Giovanni Ferrero: Giovanni Ferrero (born 21 September 1964) is an Italian businessman. He assumed the leadership of the confectionery company Ferrero SpA after the death of his brother Pietro Ferrero in 2011. He has a net worth of $24.2 billion as of May 2016, according to Bloomberg.
Document 10: Forrest Mars Sr.: Forrest Edward Mars Sr. (March 21, 1904 – July 1, 1999) was an American businessman and the driving force of the Mars candy empire. He is best known for introducing Milky Way (1923) and Mars (1932) chocolate candy bars, and M&M's (1941) chocolate candy, as well as orchestrating the launch of Uncle Ben's Rice. He was the son of candy company Mars, Inc. founder Frank C. Mars and his first wife Ethel G. Mars (née Kissack).
Document 11: Milky Way Farm: Milky Way Farm in Giles County, Tennessee, is the former estate of Franklin C. Mars, founder of Mars Candies. The property is named for the company's Milky Way candy bar. During the Great Depression, the estate was the largest employer in the county. The estate is listed on the National Register of Historic Places as an historic district; its manor house is now a venue for special events.
Document 12: Jacqueline Mars: Jacqueline Mars (born October 10, 1939) is an American heiress and investor. She is the daughter of Audrey Ruth (Meyer) and Forrest Mars, Sr., and granddaughter of Frank C. Mars, founders of the American candy company Mars, Incorporated. In 2014, "Forbes" described Mars as the 20th richest American.
Document 13: Forrest Mars Jr.: Forrest Edward Mars Jr. (August 16, 1931 – July 26, 2016) was an American heir. He was the eldest son of Audrey Ruth (Meyer) and Forrest Mars Sr., and the grandson of Frank C. Mars, the founder of Mars, Incorporated, the confectionery company. In March 2015, "Forbes" estimated his wealth to be $26.8 billion
Document 14: Snickers: Snickers is a brand name chocolate bar made by the American company Mars, Incorporated. Consisting of nougat topped with caramel and peanuts, enrobed in milk chocolate, Snickers has annual global sales of $2 billion.
Document 15: Mars, Incorporated: Mars is an American global manufacturer of confectionery, pet food, and other food products and a provider of animal care services, with US$33 billion in annual sales in 2015, and is ranked as the 6th largest privately held company in the United States by Forbes. Headquartered in McLean, unincorporated Fairfax County, Virginia, US, the company is entirely owned by the Mars family. Mars operates in six business segments around the world: Wm. Wrigley Jr. Company (Chicago, Illinois), Chocolate (Hackettstown, New Jersey; to be integrated with Wm. Wrigley Jr. Company and based in Chicago, Illinois from 2017), Petcare (Brussels, Belgium, Poncitlán and Jalisco, Mexico), Food (Rancho Dominguez, California), Drinks (West Chester, Pennsylvania), and Symbioscience (Germantown, Maryland), the company's life sciences division.
ground_truth: $26.8 billion