To provide a more accurate picture of industry trends, the value of shipments shown in the tables are expressed both in "current dollars" and in "inflation -adjusted dollars". Current dollars shows the value of the goods in the year they are produced. Constant dollars ( or real dollars) show the value of shipments as they would be valued if profuced in the base year. This permits shipment levels from different years to be compared. The constant dollar shipment (base year 1992) was derived by deflating the product class shipments from the Bureau of the Census using the Bureau of Labor Statistics producer price index.

The tables contain both industry and product shipments. The Bureau of the Census collects shipments data from individual factories (establishments) rather than at the company level.

Trade data was tabulated by identifying exports that are limited to domestic exports and are valued "free-along-ship". Imports are restricted to goods imported for consumption and are on a customs value basis.