Question: Ranked as the richest person in the world, this business magnate derived his fortune from extensive holdings through his conglomerate that was formed in what year?

Context paragraphs:
Robert Kuok: Robert Kuok Hock Nien (; born 6 October 1923), is a Malaysian Chinese business magnate and investor.  According to "Forbes", his net worth is estimated at $12.2 billion on July 2017, making him the richest person in Malaysia and second richest in Southeast Asia after Dhanin Chearavanont of Thailand, according to Forbes List of World Billionaires 2013 which Robert Kuok was placed 76th.  As of December 2012, according to the Bloomberg Billionaires Index, Kuok has an estimated net worth of $17.3 billion, making him the 40th richest person in the world.

James C. Kennedy: James Cox Kennedy (born 1948) is an American media executive and the current chair of Cox Enterprises, the media conglomerate founded by his grandfather, James M. Cox.  According to the Forbes billionaires list from 2017, he is the 105th richest person in the world, the thirty-seventh richest person in the United States, and the richest person in the state of Georgia, surpassing his aunt, Anne Cox Chambers, for the title.  He was featured in a Forbes article entitled "This Billionaire Knows The Secret To Saving A Family Business".

Alan Sugar: Alan Michael Sugar, Baron Sugar (born 24 March 1947) is a British business magnate.  He is also a media personality, politician and political adviser.  According to the Sunday Times Rich List, Sugar became a billionaire in 2015.  In 2016 they estimated his fortune at £1.15bn, and ranked him as the 95th richest person in the UK.  In 2007, he sold his remaining interest in the consumer electronics company Amstrad, his largest business venture.

Wu Yajun: Wu Yajun (; born 1964) is a Chinese businesswoman, co-founder, former CEO and current chairwoman of Longfor Properties.  She is the third richest woman in China, and the 22nd richest overall, according to the Hurun Report China Rich List 2013.  In 2012, She held the title of richest woman in China, as well as fifth richest person in China.  She lost that position to Yang Huiyan due to her divorce from Cai Kui, positioning herself as second richest woman in China.  As of March 2013 she was the 299th richest person in the world, and among the top 50 Power-women list by Forbes, with a net worth of US$4.4 billion.  She is a member of the National People's Congress.  In 2014, she was listed as the 41st most powerful woman in the world by "Forbes".

Guo Guangchang: Guo Guangchang (, born February 1967) is a Chinese billionaire business magnate and investor.  He is the chairman of Fosun International Limited and a representative of the 12th Chinese People's Political Consultative Conference.  According to Hurun Report's "2013 China Rich List" he was the 41st richest person in China.  As of 2015 he was listed as the 34th richest person in China by "Forbes", with a net worth of $7.3 billion.

Alisher Usmanov: Alisher Burkhanovich Usmanov (Russian: Алише́р Бурха́нович Усма́нов ; Uzbek: "Alisher Usmonov" ; born 9 September 1953) is an Uzbek-born Russian business magnate.  As reported by "Forbes", in 2017, Alisher Usmanov has an estimated net worth of $15.1 billion.  The December 2013 Bloomberg Billionaires Index reported an estimated net worth of $19.6 billion, making him the 37th richest person in the world.  In May 2014, "The Sunday Times" listed him as the second richest person in the UK with an estimated fortune of £10.65bn.

Grupo Carso: Grupo Carso or Grupo Sanborns SAB is a Mexican global conglomerate company owned by Carlos Slim.  It was formed in 1990 after the merger of Corporación Industrial Carso and Grupo Inbursa.  The name Carso stands for Carlos Slim and Soumaya Domit de Slim, his late wife.

Carlos Slim: Carlos Slim Helú (] ; born January 28, 1940) is a Mexican business magnate, investor, and philanthropist.  From 2010 to 2013, Slim was ranked as the richest person in the world.  He derived his fortune from his extensive holdings in a considerable number of Mexican companies through his conglomerate, Grupo Carso.

Stefan Persson (magnate): Carl Stefan Erling Persson (] ; born 4 October 1947) is a Swedish business magnate.  In March 2013, Forbes reported Persson's net worth as $28 billion making him the richest of Sweden's 12 billionaires and the 17th richest person in the world.  Persson is the chairman and main shareholder in fashion company H&M, which was founded by his father Erling Persson in 1947.  Persson took over the company from his father in 1982 and served as its manager until 1998.  Persson also owns a substantial stake in the Swedish technology company Hexagon AB.  Through his privately held real estate company Ramsbury Invest, Persson owns a large number of properties in London, Paris and Stockholm.

Lu Guanqiu: Lu Guanqiu (; born January 1945) is a Chinese entrepreneur.  He is the 18th richest person in China, according to the Hurun Report China Rich List 2013.  He is the 286th richest person in the world, and reportedly the richest person in Zhejiang Province.  He is a delegate to the Chinese National People's Congress.

Supporting paragraphs: Carlos Slim Grupo Carso
Answer: 1990