Since the 1940s, the Census Bureau has conducted various censuses - usually every 5 years - on specific areas: agriculture, economic, government, & transportation.
This is the official source for U.S. export & import statistics & responsible for issuing regulations governing the reporting of all export shipments from the U.S.
U.S. Postal Service defines ZIP codes at their convenience & may change from time to time. ZIP codes in the Economic Census & ZBP are those reported by the businesses or on administrative address lists. ZIP Code tabulation areas (ZCTAs) in Census 2000 are statistical geographic entities that approximates the delivery area for a U.S. Postal Service five-digit & three-digit ZIP Codes. ZCTAs are aggregations of census blocks that had the same predominant ZIP Code.
