Region
United States
178
China
5
Japan
3
Developing countries
2
India
2
Mexico
2
North America
2
Canada
1
Colorado
1
Delta (Region)
1
Dominican Republic
1
Europe
1
Great Plains
1
Indonesia
1
Italy
1
Middle West
1
Mississippi
1
Russia (Federation)
1
Ukraine
1
Virginia
1
Washington (State)
1
West (U.S.)
1
West Virginia
1