Subject Region
United States
33
Developing countries
7
Asia
4
Great Britain
4
Canada
3
European Union countries
3
Pacific Area
3
Europe, Eastern
2
Germany (West)
2
Group of Seven countries
2
Japan
2
Africa, West
1
Arab countries
1
Argentina
1
Barbados
1
Caribbean, English-speaking
1
China
1
Europe
1
Europe, Central
1
India
1
Italy
1
Kenya
1
Latin America
1
Madagascar
1
North America
1
Poland
1
Switzerland
1