Region
United States
637
China
15
Russia (Federation)
9
Iraq
8
Europe
5
Foreign countries
5
Great Britain
3
California, Southern
2
Hanscom AFB (Mass.)
2
India
2
Soviet Union
2
Afghanistan
1
Arctic regions
1
Asia
1
Developing countries
1
East Asia
1
England
1
Germany
1
Greece
1
Israel
1
Israël
1
Ohio
1
Philippines
1
Ravenna
1
Saudi Arabia
1
South America
1
Syria
1
Texarkana
1
Texas
1
États-Unis
1