37 visiting now: 18 USA 
10 Singapore 
5 Canada 
3 UK 
1 Germany 
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1 Saudi Arabia 
1 Belgium 
1 China 
10 Singapore 5 Canada 3 UK 1 Germany 1 Iran 1 Saudi Arabia 1 Belgium 1 China 10 Singapore 5 Canada 3 UK 1 Germany 1 Iran 1 Saudi Arabia 1 Belgium 1 China