The interactive map shows population change in New Zealand between 2001 and 2013.
Earlier we published a blog post by the economist Aaron Schiff who created density dot maps - which showed one blue dot for each new person in census area units that experienced population growth over this time, and one red dot for each person lost in areas where the population shrank.
See below for the map if viewing on mobile
Mr Schiff had asked if anyone would like to help make an interactive map - Wellington-based data visualisation firm Dumpark produced this one over the week. It allows readers to see patterns for each city and all the rural areas.
You can select a map for all ages and for 20 to 34 age group.