Region
United States
48
Developing countries
22
East Asia
7
Eastern Europe
6
Europe, Eastern
6
European Economic Community countries
6
Asia
5
Latin America
5
China
4
European Union countries
4
Japan
4
Europe
3
Great Britain
3
Israel
3
Pacific Area
3
Central Europe
2
Europe, Central
2
Former Soviet republics
2
Africa, North
1
Arab countries
1
Canada
1
Greece
1
Group of Seven countries
1
Islamic countries
1
Middle East
1
New England
1
North Africa
1