State versus County and Federal District Figures

County figures do not always sum to state totals for two reasons. First, small differences may occur because the original data source rounds each county and state estimate separately, introducing the possibility of small rounding errors when county estimates are summed. Second, for a few small counties, values may be suppressed by the original data source to protect privacy. This occurs, for example, in census data and IRS income data. State values -- whenever available separately from the original data source --will often include these suppressed values within their totals.

Federal district values are derived by summing up the values for each county within the federal district's borders. This means that they are subject to the same limitations as county level data. Accordingly, when a federal district follows state boundaries, the federal district values may differ from the state values whenever the sum of the county values differs from the state total.