Region
United States
18
Asia
5
China
5
Africa
2
Europe
2
Russia (Federation)
2
Africa, North
1
Arab countries
1
Croatia
1
Europe, Central
1
Europe, Eastern
1
Europe, Northern
1
European Economic Community countries
1
European Union countries
1
Great Britain
1
India
1
Japan
1
Middle East
1
North America
1
Romania
1