Data The unit of analysis is the New Zealand census area unit, and the point in time for the cross-sectional analysis, is March 6, 2006, the date of the last New Zealand census. There are 398 census area units within the ARC, of which sufficient data could be collected on 318. The sources of data are Statistics New Zealand, Land Transport New Zealand, ARTA, and the University of Auckland. ArcGIS was used in the compilation of data having a spatial dimension.