21 visiting now: 8 USA 
7 China 
1 Germany 
1 South Africa 
1 Belgium 
1 Netherlands 
1 Brazil 
1 Vietnam 
7 China 1 Germany 1 South Africa 1 Belgium 1 Netherlands 1 Brazil 1 Vietnam 7 China 1 Germany 1 South Africa 1 Belgium 1 Netherlands 1 Brazil 1 Vietnam