(NA) = Data not available.
(Other Metropolitan Areas) = An aggregate category for metropolitan areas whose export values are suppressed because they could reveal sensitive information that could be linked to specific companies.
(Unknown) = Instances where there was insufficient information to allocate exports to a metropolitan area.
(Crossovers) = Instances where the origin of movement of the exports was from a ZIP code shared by two or more adjacent metro areas. In these instances it was impossible to assign the exports to a single metro area.
(Non Metropolitan Areas) = Instances where the origin of movement of the exports were from a ZIP code associated with a rural area.