I guess you know that New Zealand has been allocated ZL and ZM prefixes.
ZL is generally available. ZM is a special prefix, which is used on special events.
New Zealand represents 5 countries as per DXCC list: ZL1-4,6; ZL5; ZL7; ZL8; ZL9 (see the map).
The population of ZL community is about 5,200 people.
Amateur operators certificates are issued by Ministry of Economic development. Radio Spectrum Management Group. With removing of Morse Code requiremenmts for HF access there is only one grade as of June 2004: