Why are maps of revenues or shipments not available for some industries?
In some industries, data were withheld for particular states to avoid disclosure of information about particular companies, and generally these states are shown in gray (N/A). If the output (sales, revenue, shipments) from those states accounts for more than 25 percent of the national total, so that the distribution of the remainder might give a misleading impression, maps of output, output per capita, and output per employee are not shown.
