This dataset is the major released version of the annually released regional council constituency boundaries as at 1 January 2018, clipped to the coastline.This clipped version contains 55 constituencies, excluding area outside constituency, and has been created for map creation/cartographic purposes and may not fully represent the official full extent boundaries.Constituencies are established under the Local Electoral Act 2001 and result from the division of a region for electoral purposes.If a regional council decides to have a Māori constituency, the constituencies within the region are known as general constituencies and Māori constituencies.Constituencies are divisions of regional council areas. They are defined at meshblock level, and do not coincide with statistical area 1 (SA1) or statistical area 2 (SA2). They are created, based on population, to be the voting areas within councils. Constituencies are required to reflect communities of interest. Their boundaries, so far as is practicable, coincide with those of territorial authorities or wards. The boundaries of constituencies may be reviewed before each three-yearly local government election. Regional councils must review their representation arrangements at least once every six years. The provisions for such reviews are in the Local Government Act 2002. Constituencies are numbered based on their corresponding regional council. Each constituency has a unique four-digit code. The first two digits represent the regional council that the constituency lies within. The last two digits are sequential and represent the number of constituencies within a regional council. For example, the West Coast Regional Council (12) contains three constituencies, which are coded 1201, 1202, and 1203.The following table lists the total number of constituencies by year:YearConstituency totals198996199278199583199872200067200167200269200369200469200569200669200769200862200962201062201156201256201356201459201559201659201755201855Digital boundary data became freely available on 1 July 2007.