Statistics New Zealand defines urban areas of New Zealand for statistical purposes (they have no administrative or legal basis). The urban areas comprise cities, towns and other conurbations (an aggregation of urban settlements) of a thousand people or more. In combination, the urban areas of the country constitute New Zealand's urban population. As of June 2018, the urban population made up 88.5% of New Zealand's total population. There are four classes of urban area under SSGA18: