Region
Alabama
2
Alaska
3
Arizona
2
Arkansas
2
California
2
Colorado
2
Connecticut
2
Delaware
2
Europe
1
Florida
2
Georgia
2
Germany
1
Guam
2
Hawaii
2
Indiana
1
Iowa
1
Japan
3
Kentucky
2
Louisiana
2
Maine
2
Maryland
2
Massachusetts
2
Michigan
1
Minnesota
2
Mississippi
2
Missouri
2
Montana
2
Nebraska
2
Nevada
2
New Hampshire
1
New Jersey
1
New Mexico
2
New York (State)
2
North America
1
North Carolina
2
North Dakota
1
OECD countries
2
Oklahoma
1
Oregon
2
Pennsylvania
1
Rhode Island
2
South Carolina
2
Tennessee
2
Texas
2
United States
589
United States Virgin Islands
1
Utah
2
Vermont
1
Virginia
2
Washington (D.C.)
2
more ...