Region
Asia
2
Asia --
2
Asia, Southeastern
1
Asia, Southeastern --
1
Bulgaria
1
Bulgaria --
1
Central America
1
Central America --
1
Chile
1
Chile --
1
China
2
China --
2
Cuba
1
Cuba --
1
Developing countries
1
Developing countries --
1
India
1
India --
1
Iran
2
Iran --
2
Israel
1
Israel --
1
Latin America
1
Latin America --
1
Malaysia
1
Mexico
1
Mexico --
1
Soviet Union
5
Soviet Union --
6
United States
22
United States --
Vietnam
1
Vietnam --
1
central America
1