Census regions: 4 groups
1 = NORTHEAST
2 = NORTH CENTRAL
3 = SOUTH
4 = WEST

Census subdivisions within regions
1 = NEW ENGLAND
2 = MIDDLE ATLANTIC
3 = EAST NORTH CENTRAL
4 = WEST NORTH CENTRAL
5 = SOUTH ATLANTIC
6 = EAST SOUTH CENTRAL
7 = WEST SOUTH CENTRAL
8 = MOUNTAIN
9 = PACIFIC