Region
Soviet Union --
Soviet Union
17
United States --
13
United States
12
Developing countries
3
Developing countries --
2
Russia --
2
Afghanistan
1
Afghanistan --
1
Africa
1
Africa --
1
Asia
1
Asia --
1
Eastern Europe
1
Europe --
1
Europe, Eastern
1
Europe, Eastern --
1
Germany
1
Germany --
1
Korea
1
Korea --
1
Middle East
1
Middle East --
1
Russia (Federation) --
1
South Asia
1
South Asia --
1
Yemen (People's Democratic Republic)
1
Yemen (People's Democratic Republic) --
1