1 United States 72 58.5%2 Germany 12 9.8%3 China 10 8.1%4 Republic of Korea 5 4.1%6 Egypt 3 2.4%7 Serbia 3 2.4%8 Philippines 2 1.6%9 France 2 1.6%10 Kazakhstan 2 1.6%11 Indonesia 2 1.6%12 Iran 1 0.8%13 Italy 1 0.8%14 Netherlands 1 0.8%16 Ukraine 1 0.8%17 United Kingdom 1 0.8%
