Central South

Includes the states of Arizona, Arkansas, Colorado, Louisiana, Mississippi, Oklahoma, New Mexico, Texas and Utah.

Midwest Plains

Includes the states of Iowa, Kansas, Minnesota, Nebraska, North Dakota, South Dakota and Wisconsin.

Mountain West

Includes the states of California, Hawaii, Idaho, Montana, Nevada, Oregon, Washington and Wyoming.

Northeast

Includes the states of Connecticut, Delaware, Indiana, Maine, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, Virginia and West Virginia.

Southeast Midlands

Includes the states of Alabama, Florida, Georgia, Illinois, Kentucky, Missouri, North Carolina, South Carolina and Tennessee.

National Data Center

Includes phone data collection efforts across the U.S.