Region
United States
United States --
46
Soviet Union
14
Soviet Union --
12
Developing countries
4
Developing countries --
4
Europe
4
Russia
4
United states --
4
Europe --
3
Russia (Federation)
3
Russia (Federation) --
3
Great Britain
2
Great Britain --
2
Japan
2
Japan --
2
Russia --
2
Africa
1
Africa --
1
Canada
1
Eurasia --
1
France
1
France --
1
Germany
1
Germany --
1
Korea (North)
1
Korea (North) --
1
Yugoslavia
1
Yugoslavia --
1