Region
United States
United States --
183
China --
22
China
21
Soviet Union --
19
Soviet Union
18
United states --
14
Asia
13
Asia --
13
Europe --
11
Japan
11
Japan --
11
Middle East
11
Europe
10
Middle East --
10
Israel
9
Israel --
9
Latin America
7
Latin America --
7
Asia, Southeastern
5
Asia, Southeastern --
5
Central America --
5
Great Britain --
5
Central America
4
East Asia
4
Great Britain
4
Vietnam --
4
Caribbean Area
3
Caribbean Area --
3
Developing countries --
3
East Asia --
3
Europe, Eastern
3
Europe, Eastern --
3
Indonesia
3
Indonesia --
3
Iran --
3
Pacific area --
3
Philippines
3
Philippines --
3
Russia (Federation)
3
Russia (Federation) --
3
Taiwan --
3
Vietnam
3
Afghanistan
2
Afghanistan --
2
Argentina
2
Argentina --
2
Australia
2
Australia --
2
Chile
2
more ...