NZ port refers to the NZ port where the passenger was processed by Customs. Before September 1997, NZ port referred to the first NZ port of arrival or last NZ port of departure.
In arrival series, the closest overseas port is the last port that the passenger's flight visited before it arrived in New Zealand. This may not be the person's port of origin.
In departure series, the closest overseas port is the first port that the passenger's flight visited after it departed New Zealand. This may not be the person's destination.
At URL provided, select 'Tourism > International Travel and Migration - ITM > Total passenger movements by NZ port and selected closest overseas ports (Monthly)'. All variables were selected to produce this dataset.