how many 5 digit zip codes in the us
ZIP Code There are over 42,000 ZIP Codes in the United States.[20] ZIP Codes are used not only for tracking of mail but also in gathering geographical statistics in the United States. The U.S. Census Bureau calculates approximate boundaries of ZIP Codes areas, which it calls ZIP Code Tabulation Areas (ZCTAs). Statistical census data is then provided for these approximate areas. The geographic data provided for these areas includes the latitude and longitude of the center-point of the ZCTAs. There are approximately 32,000 ZCTAs. The reason that there is not one ZCTA for every ZIP Code is that PO Boxes are excluded, since only populated areas are included in the Census data.[21] The Census Bureau provides many statistical data sets for ZIP Codes, but does not keep up-to-date datasets of all ZCTAs. Complete datasets providing a similar approximate geographic extent are commercially available.
Former Australian dialling codes In Australia, as in other countries, due to the increase in subscriber uptake of services such as extra telephone lines in homes, mobile phones and other services, the previous numbering plan was being stretched to its limit. It was decided to reduce the number of area codes and lengthen all subscriber numbers by one or two digits. This occurred between 1994 and 1998, and was done progressively to ensure as little inconvenience and confusion as possible. The gradual change was also to avoid number clashes, a situation where two subscribers in two completely different locations have technically the same telephone number if dialled in their entirety. The first numbers to be converted to eight digits were numbers in the 99x xxxx and 99 xxxx ranges in the suburb of Mona Vale in Sydney, which all became 999x xxxx or 9999 xxxx on 25 July 1994. The final codes changed to eight digits were the Queensland (070), (071), (076), (077) and (079) codes, which all changed to (07) 4yxx xxxx on 10 November 1997.