Region
United States
49
Developing countries
10
China
8
India
6
Africa South of the Sahara
4
Asia
4
Brazil
3
Japan
3
Outer space
3
Africa
2
Korea
2
Korea (South)
2
Latin America
2
Arab countries
1
Bikini Atoll (Marshall Islands)
1
California
1
Colorado
1
Congo (Democratic Republic)
1
Europe
1
Former Soviet republics
1
France
1
Iran
1
Islamic countries
1
Livermore
1
Los Angeles (Calif.)
1
Russia (Federation)
1
Soviet Union
1
Tamil Nadu
1
Tibet Region
1
U.S. states
1