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We can see that the north east side of the country has higher concentration of Maori folks.
I have downloaded the population data with ethnicity information from Statistics New Zealand. (http://nzdotstat.stats.govt.nz/wbos/Index.aspx) and the boundary data from this page (http://www.stats.govt.nz/browse_for_stats/Maps_and_geography/Geographic-areas/digital-boundary-files.aspx) at the same website.