These maps show projected trends in the experience of natural increase, zero natural increase, and natural decrease, according to Statistics New Zealand's 2013-base Update projections. White denotes natural increase, pale blue denotes zero natural increase, dark blue denotes natural decrease. Natural decrease has not yet occurred at regional council area level. However, the medium variant assumptions indicate it will be the experience of three council areas within one decade, and of eight in approximately two decades. The data are drawn from the Royal Society Marsden project The ebbing of the human tide. What will it mean for the people? and have been converted for visualisation by the CaDDANZ Population Atlas research team. See for additional detail. See for additional detail and important methodological notes.