Region
Developing countries
4
Europe, Eastern
3
Former Soviet republics
2
Japan
2
Mexico
2
Africa, French-speaking Equatorial
1
Africa, French-speaking West
1
Albania
1
Arab countries
1
China
1
European Economic Community countries
1
Germany (East)
1
Germany (West)
1
Hong Kong (China)
1
Korea
1
Russia (Federation)
1
Thailand
1
United States
1