The 2018 Census of population is just six weeks away with one of the biggest changes in more than a century of the nationwide head-counting.
The Census, the 34th head-count since the first in 1851, is expected to be done mainly online.
The goal of the Census is to provide an accurate picture of New Zealand population structure, households and families, cultures and identities, education and training, employment status, incomes, transport and health.
A Statistics NZ spokesperson said yesterday letters will be sent to about 1.8 million households from about February 24, with each household getting an access code to do the on-line bit by the Census date of Tuesday, March 6.
Statistics NZ, which has conducted tests with a population sample to assess how it will run, said the 1.8 million represents about 80 per cent of the nation's households, and it will still have to visit the other one-fifth.
Steps are also in place to help those unable to do it or shy-of the on-line process, and to engage with households which don't appear to be participating.
The organisation expected about 70 per cent will do it online, with the paper option common to the days of Census agents knocking at the front door to deliver the papers and then to collect them coming to an end.
While the Census covers a range of topics with questions chosen to elicit the information to help plan the country's needs, much interest will surround how close the national population gets to 5 million.
It reached 1 million in 1908, 2 million in 1952, 3 million in 1973, 4 million in 2003, and totalled 4,242,048 at the last Census in 2013.
The population of the five territorial local authorities in Hawke's Bay from Wairoa to the Tararua district was 167,979, and the Hawke's Bay Region, defined by the regional council boundaries excluding Tararua and including small parts of the Taupo and Rangitikei districts passed 150,000 for the first time.
While the population grew in Napier and Hastings it had decreased in the three outlying districts of Wairoa, Central Hawke's Bay and Tararua.
A 2003 forecast that it would reach 4.81 million in 2046 is proving to be way short of the mark, with StatsNZ estimating it was 4.79 million at the end of last June, and its population clock last night calculating it was almost 4.8 million.
The population is growing at a rate of about one person every 5 minutes and 6 seconds, with births averaging one every 8 minutes and 46 seconds, deaths averaging one every 17 minutes and 4 seconds, and net migration gain of one New Zealand resident every 7 minutes and 6 seconds.
Censuses are held every five years, but the schedule was put back two years when the 2011 count was unable to be done because of the Canterbury earthquake.