An official count of the people in New Zealand goes back as far as 1842. But New Zealand's first official Census was in 1851. That asked questions on aspects of life just as it does today - including ethnicity, education, and disability.
It counted only European settlers, however, and a separate Maori Census was taken from 1857 to 1858. From 1874, the Maori Census was about the same time as the European Census until the two were integrated in 1951.
Several topics must, by law, be included. Under the 1975 Statistics Act every person in New Zealand on Census day is asked his or her name and address, sex, age and ethnicity.
THE QUESTIONS
Over time, questions have been added and omitted in line with what was considered salient by government departments at the time.
The 1906 Census asked for the number of poultry - geese, ducks, fowls, turkeys or other - the number of beehives, and the amount of honey and beeswax they produced in a year.
From 1936 to 1971 questions about war participation were asked, and in 1971 people were asked whether their dwelling had flushing toilets, telephones, fridges, deep freezes or powered lawnmowers.
The information gathered is used by businesses, iwi, councils, and the Government to make decisions on issues that affect the country.
Billions of dollars' worth of decisions are made in areas including health, education and transport, based on the data gathered.
A Northland District Health Board statement recently said for every person that did not fill in a Census form, it missed out on up to $3000 of funding.
Filling in forms is required by law - the 1877 Census Act cautioned those who refused to fill in their forms were liable for a £20 fine.
Under the newer 1975 Statistics Act, those who don't participate or who provide false or incomplete information can be fined up to $500, with a further $20 a day until the forms are completed.
Census spokeswoman Vikki Carter says about 70 people were prosecuted for failing to complete the 2006 survey, with more than half convicted. "A number of people chose to complete the form once a prosecution was taken."
Ms Carter says Statistics New Zealand's first priority is to encourage people to complete the survey by explaining its importance.
Even passing tourists are required to take part.
Census officials will be at airports tomorrow and forms have already been dropped off to cruise ships, hotels and even to those travelling through the country in campervans, she says.
The accuracy of the Census depends on everyone in New Zealand filling in their forms and answering all questions that apply, Ms Carter says.
THE OPPOSITION
The Census has not been without controversy. Ian Brackenbury Channell, better known as the Wizard of New Zealand (as nicknamed in 1990 by then Prime Minister Mike Moore), has famously avoided filling out the Census by doing everything from casting a "disappearing spell" on himself, to heading offshore in a small boat for the day.
The Wizard has campaigned against the Census since 1975, claiming the information gathered is not essential for the running of the country and the process is a waste of public money.
The "Jedi phenomenon" took off in 2001 when about 50,000 people listed their religion as Jedi - an ancient order from the Star Wars films - in a lighthearted jest at the official document.
The phenomenon was an international movement, but by the 2006 Census, the number of "Jedi" in New Zealand had fallen to about 20,000.
Although a number of more serious groups have campaigned for their religion or ethnicity to be added to the Census, Ms Carter says there is no set number which must be met for a religion to be official, and there is an option for those that aren't listed to write it in themselves.
The Libertarianz political party has again urged "anyone who objects to the coercive nature of the five-yearly Census" to destroy their papers.
The party's leader, Richard McGrath, says members of the party planned to burn, shred, deface or simply ignore the documents.
THE ETHNICITY DEBATE
Dr Muriel Newman, the founder and director of the New Zealand Centre for Political Research, says since ethnicity questions were changed in the 1980s from an objective measure based on percentage to the modern-day subjective self-definition of heritage, the results had been interpreted in a way which dramatically overstates the number of people of Maori descent in New Zealand.
"If someone has a distant ancestor who was Maori, and ticks the Maori option as well as other options to reflect their more recent and dominant ancestry, all of those other ethnicities will be ignored and they will be classified by Statistics NZ as Maori.
"This practice grossly exaggerates the number of Maori in New Zealand with serious financial consequences, since these statistics are used as a basis for the allocation of resources for race-based Maori-only policies and funding."
Because of the rapid rate of intermarriage in New Zealand the boundaries of Maori ethnicity have blurred to such an extent that accurate ethnic categorisation has become almost impossible, Dr Newman says.
In 1986, the year the ethnicity question was changed on the Census form, 20,313 people objected by ticking the "other" box and writing "New Zealander".
In 1991, 20,800 did so, and in 1996, the number jumped to 58,614. By 2001, it had increased to 85,300, and at the last Census in 2006, 429,429 people called themselves a "New Zealander".
THE COLLECTORS
Behind the huge Census operation are more than 7500 collectors who have delivered forms to about 4.2 million people and 1.6 million homes.
Census community liaison officer Saumalu Kali has been visiting Pacific Island communities explaining the Census and its importance. She says she has visited 45 churches since late October spreading the message.
"I must admit, lots of them didn't know about the Census," Ms Kali says.
"Even though they've been here in New Zealand before, they probably just didn't fill in their form."
Some were hesitant to fill in the Census due to concerns about confidentiality, she says.
Ms Kali says she managed to change some opinions by explaining that filling in Censuses meant more funding for education, hospitals, housing and early childcare centres.
Census collator Chris Schreuder has been busy on the streets of Whangarei, delivering 248 dwelling and 649 individual forms since February 16.
Working in the Te Tai Tokerau district - which has historically had low Maori participation rates - Ms Schreuder says boosting participation rates to ensure everyone filled in the form was a key target outlined in her training. "Most people go, 'oh yes, we've been expecting you'."
Ms Schreuder says most people have been "really, really friendly" and she has had many invitations to come in for a cup of tea.
"Of course we're not allowed to go in. If we stopped and had a cup of tea with every single person that we visited or that invited us in, we'd be spending most of the year trying to deliver these things."
A single mother and applied art student, Ms Schreuder says the job appealed to her as she is "very much a people person".
"For me, going around and knocking on people's doors and having that sort of contact [is great]. I get my energy from being with people and talking to people so for me, it's a great job."
