Region
Soviet Union
Soviet Union --
16
United States
3
United States --
3
Afghanistan
1
Afghanistan --
1
Angola
1
Angola --
1
Developing countries
1
Eastern Europe
1
Europe --
1
Europe, Eastern
1
Europe, Eastern --
1
Germany
1
Germany --
1
Russia
1
Russia (Federation)
1
Russia (Federation) --
1
Russia --
1