Region
United States
18
China
10
Europe
7
Communist countries
6
Europe, Eastern
4
Developing countries
3
Brazil
2
Great Britain
2
Japan
2
Latin America
2
Southern States
2
Soviet Union
2
Argentina
1
Asia
1
Berlin
1
Germany
1
Grande-Bretagne
1
Indonesia
1
Malaysia
1
Manufacturing industries
1
Mexico
1
Peru
1
Scandinavia
1
États-Unis
1