Region
United States --
United States
6
Russia --
2
Afghanistan
1
Afghanistan --
1
Asia
1
Asia --
1
Canada --
1
Developing countries
1
Europe --
1
Great Britain
1
Great Britain --
1
Israel --
1
Korea
1
Korea --
1
Nicaragua
1
Nicaragua --
1
Russia
1
South Africa
1
South Africa --
1
Soviet Union
1
Soviet Union --
1