This dataset is the definitive set of annually released meshblock boundaries at 1 January 1991. Stats NZ maintains an annual meshblock geography for collecting and producing statistical data. This allows data to be compared over time. A meshblock is the smallest geographic unit for which statistical data is collected and processed by Stats NZ. A meshblock is defined by a geographic area, which can vary in size from part of a city block to a large area of rural land. Each meshblock borders on another to form a network covering all of New Zealand, including coasts and inlets and extending out to the 200-mile economic zone.. Meshblocks are added together to build up larger geographic areas such as area units and urban areas. They are also used to define electoral districts, territorial authorities and regional councils. Full metatdata can be found here: http://www.stats.govt.nz/browse_for_stats/people_and_communities/Geographic-areas/digital-boundary-files.aspx#metadata.