http://socrates.berkeley.edu/~zook/domain_names/

Overview of Current Geography of Domains
As of January 2000 there were 10,008,475 com, org, net and edu domains registered worldwide. There are another 3,344,305 country code TLDs (.uk or .de) domains registered as well. That's about 2.2 Intenet domains per 1000 people worldwide. In the US, the figure is 25.2 domains per 1000 people.
CONCENTRATIONS OF DOMAIN NAMES
Combined (com, org, net, edu and country code TLDs) there are 13.35 million domains. They are distributed as follows….

The US has 50.0 percent                 
        California has 11.5 percent             
                Los Angeles (CMSA) has 5.6 percent      
                San Francisco (CMSA) has 3.9 percent    
        New York State has 4.3 percent          
                New York (CMSA includes NJ and CT) has 5.9 percent      
Germany has 8.6 percent                 
The UK has 8.5 percent                  
John
sosebee@bellsouth.net
Network Engineering
(770) 522-4000