This is according to the Forbes magazine… this is top 10
1 William Gates III United States 50 50.0 United States 2 Warren Buffett United States 75 42.0 United States 3 Carlos Slim Helu Mexico 66 30.0 Mexico 4 Ingvar Kamprad Sweden 79 28.0 Switzerland 5 Lakshmi Mittal India 55 23.5 United Kingdom 6 Paul Allen United States 53 22.0 United States 7 Bernard Arnault France 57 21.5 France 8 Prince Alwaleed Bin Talal Alsaud Saudi Arabia 49 20.0 Saudi Arabia 9 Kenneth Thomson & family Canada 82 19.6 Canada 10 Li Ka-shing Hong Kong 77 18.8 Hong Kong 11 Roman Abramovich Russia 39 18.2 United Kingdom 12 Michael Dell United States 41 17.1 United States 13 Karl Albrecht Germany 86 17.0 Germany 14 Sheldon Adelson United States 72 16.1 United States 15 Liliane Bettencourt France 83 16.0 France 15 Lawrence Ellison United States 61 16.0 United States 17 Christy Walton United States 51 15.9 United States 17 Jim Walton United States 58 15.9 United States 19 S Robson Walton United States 62 15.8 United States 20 Alice Walton United States 56 15.7 United States 21 Helen Walton United States 86 15.6 United States 22 Theo Albrecht Germany 83 15.2 Germany 23 Amancio Ortega Spain 70 14.8 Spain 24 Steven Ballmer United States 50 13.6 United States 25 Azim Premji India 60 13.3 India 26 Sergey Brin United States 32 12.9 United States 27 Larry Page United States 33 12.8 United States 28 Abigail Johnson United States 44 12.5 United States 29 Nasser Al-Kharafi & family Kuwait 62 12.4 Kuwait 29 Barbara Cox Anthony United States 82 12.4 United States 29 Anne Cox Chambers United States 86 12.4 United States 32 Stefan Persson Sweden 58 12.3 Sweden 33 Charles Koch United States 70 12.0 United States 33 David Koch United States 65 12.0 United States 35 Raymond, Thomas & Walter Kwok Hong Kong NA 11.6 Hong Kong 36 Adolf Merckle Germany 71 11.5 Germany 37 Sulaiman Bin Abdul Al Rajhi Saudi Arabia 86 11.0 Saudi Arabia 37 Vagit Alekperov Russia 55 11.0 Russia 37 Silvio Berlusconi Italy 69 11.0 Italy 37 Lee Shau Kee Hong Kong 78 11.0 Hong Kong 41 Vladimir Lisin Russia 49 10.7 Russia 42 Michael Otto & family Germany 62 10.4 Germany 43 Pierre Omidyar United States 38 10.1 United States 44 Leonardo Del Vecchio Italy 70 10.0 Italy 44 Michele Ferrero & family Italy 79 10.0 Monaco 44 Forrest Mars Jr United States 74 10.0 United States 44 Jacqueline Mars United States 66 10.0 United States 44 John Mars United States 69 10.0 United States 44 Viktor Vekselberg Russia 48 10.0 Russia 50 Mikhail Fridman Russia 41 9.7 Russia 51 Spiro Latsis & family Greece 59 9.1 Switzerland 52 John Kluge United States 91 9.0 United States 53 Carl Icahn United States 70 8.7 United States 53 Kirk Kerkorian United States 88 8.7 United States 55 Birgit Rausing & family Sweden 82 8.6 Switzerland 56 Mukesh Ambani India 48 8.5 India 56 Serge Dassault & family France 80 8.5 France 56 Hans Rausing Sweden 80 8.5 United Kingdom 59 Galen Weston & family Canada 65 8.4 Canada 60 Susanne Klatten Germany 43 8.1 Germany 61 Rudolf August Oetker & family Germany 89 8.0 Germany 62 Oleg Deripaska Russia 37 7.8 Russia 63 Sumner Redstone United States 82 7.7 United States 64 Alexei Mordashov Russia 40 7.6 Russia 65 Donald Newhouse United States 76 7.5 United States 65 Samuel Newhouse Jr United States 78 7.5 United States 65 Alain & Gerard Wertheimer France NA 7.5 France 65 Reinhold Würth Germany 70 7.5 Germany 69 Joseph & Moise Safra Brazil NA 7.4 Brazil 70 Philip Knight United States 68 7.3 United States 71 George Soros United States 75 7.2 United States 72 Ernesto Bertarelli Switzerland 40 7.1 Switzerland 72 Suleiman Kerimov Russia 40 7.1 Russia 74 Philip & Cristina Green United Kingdom NA 7.0 Monaco 74 Francois Pinault France 69 7.0 France 74 August von Finck Germany 76 7.0 Switzerland 77 Mohammed Al Amoudi Saudi Arabia 60 6.9 Saudi Arabia 77 Abdul Aziz Al Ghurair & family United Arab Emirates 52 6.9 United Arab Emirates 79 Maria-Elisabeth & Georg Schaeffler Germany NA 6.8 Germany 80 Charles Ergen United States 53 6.7 United States 80 Edward Johnson III United States 75 6.7 United States 82 Kun-Hee Lee & family South Korea 64 6.6 South Korea 82 Stefan Quandt Germany 40 6.6 Germany 84 Saleh Bin Abdul Aziz Al Rajhi Saudi Arabia 94 6.5 Saudi Arabia 84 Rafael del Pino & family Spain 85 6.5 Spain 84 Stanley Ho Hong Kong 84 6.5 Hong Kong 84 Maersk Mc-Kinney Moller Denmark 92 6.5 Denmark 84 Keith Murdoch United States 75 6.5 United States 89 Philip Anschutz United States 66 6.4 United States 89 Hasso Plattner Germany 62 6.4 Germany 89 Vladimir Potanin Russia 45 6.4 Russia 89 Mikhail Prokhorov Russia 40 6.4 Russia 93 Vladimir Yevtushenkov Russia 57 6.3 Russia 94 Micky Arison United States 56 6.1 United States 94 Curt Engelhorn Germany 79 6.1 Switzerland 94 Friedrich Flick Jr Germany 79 6.1 Austria 94 German Khan Russia 44 6.1 Russia 94 Ronald Perelman United States 63 6.1 United States 94 Johanna Quandt Germany 78 6.1 Germany 100 Dan Duncan United States 73 6.0 United States