<iframe src="https://exploratory.io/viz/kanaugust/7999323729445690?embed=true" frameborder="0" width="100%" height="100%" > </iframe>
I have downloaded the data from Statistics New Zealand (http://nzdotstat.stats.govt.nz/wbos/Index.aspx) and used the population of people and sheep in 2013 for the comparison. The regional boundaries data was originally downloaded from the same website and converted to GeoJSON, which is available at Map Gallery page. (https://exploratory.io/map)