National Population Estimates: December 2009 quarter



This release contains estimates of the total population of New Zealand at 31 December 2009. Tables are included at the end of this release with estimated resident population and population change, estimated resident population by broad age group and sex, and by five-year age groups. Estimates by single year of age are available via Infoshare on the Statistics New Zealand website (demography age estimates in the 'Population' category).

Population estimates give the best available measure of the size and age-sex structure of the population usually living in an area. Estimates are based on the latest census data and on births, deaths, and migration since the census. National population estimates are published quarterly and subnational population estimates are published annually.

The estimates in this release are provisional. They incorporate provisional estimates of the number of births and deaths that occurred in the December 2009 year. Final estimates will be released on 14 May 2010. In addition, population estimates after 30 June 2006 will be revised following results from the 2011 Census of Population and Dwellings.

In this release, a special topic examines trends in the number of children (0–14 years) between 1969 and 2009. Previous releases have included special topics on trends in the working-age population, an international comparison of the percentage of population aged 65+, and trends in the components of population change.

Estimated resident population at 31 December 2009

The estimated resident population of New Zealand was 4,346,700 at 31 December 2009, comprising 2,133,700 males and 2,212,900 females. At 31 December 2009, there were 96 males for every 100 females.

                   Graph, estimated resident population, 1995–2009. Graph, Annual population change 1995–2009.

Annual population change

In the December 2009 year, the estimated resident population grew by 55,100 (1.3 percent), compared with 39,000 (0.9 percent) in the previous December year. The population growth in the December 2009 year was higher than the average annual increase of  49,500 (1.2 percent) recorded during the 10-year period from December 1999 to December 2009, and the highest growth since the year ended September 2004, when it was 56,000 (1.4 percent).

The population growth for the December 2009 year resulted from a natural increase (excess of births over deaths) of 33,900 and a net permanent and long-term (PLT) migration gain of 21,300 (largely due to fewer PLT departures). The level of net PLT migration was the highest for a December year since 2003 (34,900). Historically, natural increase has been the dominant element in population growth. Over the last 40 years, natural increase accounted for four-fifths of New Zealand's total population growth. During the December 2009 year, natural increase accounted for three-fifths of population growth.

Quarterly population change

During the December 2009 quarter, New Zealand's estimated resident population grew by 15,400 (0.4 percent). This growth resulted from a natural increase of 8,500 and a net PLT gain of 6,900. In comparison, for the December 2008 quarter, natural increase was slightly higher (9,100) while net migration was lower at 2,700 which resulted in a quarterly population growth of 11,700 (0.3 percent).

Median age

New Zealand has an ageing population because of a shift to sustained low fertility and low mortality rates. This shift is also observed in other Organisation for Economic Co-operation and Development (OECD) countries. At 31 December 2009, half of New Zealand's population was over the age of 36.6, compared with a median age of 34.2 years a decade earlier.

Graph, estimated resident population, 1995–2009.  

The gap between male and female median age has increased over time. In 1936 the median ages for males and females were 28.4 and 28.7 years, respectively. The median age for males is now 35.5 years, while for females it is 37.5 years. Since 1936 the gap between the male and female median ages has increased from 0.3 years to 2.0 years. The lower median age for males reflects their lower life expectancy of 78.2 years, compared with 82.2 years for females (New Zealand abridged life table, 2006–08).

Changes in age composition

The age composition of New Zealand's population has changed over the past decade. In the 10 years ended 31 December 2009, the number of children (aged 0–14 years) grew to 892,600, an average annual increase of 1,400 (0.2 percent). For the year ended 31 December 2009, the increase in the number of children of 3,100 (0.3 percent) was above the annual average for the decade. At 31 December 2009, children accounted for 21 percent of the New Zealand population, down from 23 percent at 31 December 1999. Trends in the number of children, 1969–2009, are discussed further below (page 5).

At 31 December 2009, the population aged 15–39 years reached 1,494,200, an increase of 14,100 (1.0 percent) compared with the December 2008 figure. In the 10 years ended December 2009, the average annual increase for this age group was lower, at 8,300 (0.6 percent). The population aged 15–39 accounted for 34 percent of the New Zealand population at 31 December 2009, down from 37 percent a decade earlier.

Graph, Average annual population change, by age group and sex, 10 years ended December 2009.  

Thirty-two percent of the population were aged 40–64 years at 31 December 2009, up from 29 percent in 1999. This age group increased by 22,700 (1.7 percent) in the year ended 31 December 2009, to reach 1,399,800. This was below the average annual increase of 28,800 (2.3 percent) for the 10 years ended December 2009.

During the December 2009 year, the population aged 65–79 years increased by 10,600 (2.6 percent) to reach 412,200. In the 10 years ended December 2009, the population aged 65–79 years grew at an average annual rate of 1.8 percent (6,600). The proportion of the population aged 65–79 years was 9.5 percent at 31 December 2009, up from 9.0 percent in 1999.

In the 10 years ended December 2009, there was also an increase in the proportion of the population aged 80 years and over (80+), from 2.7 percent in 1999 to 3.4 percent in December 2009. The 80+ population reached 147,900 at 31 December 2009, an average annual increase of 4,300 (3.5 percent) over the decade. The size and growth rate of this age group varied significantly by sex. The average annual growth rate for males for the decade ended December 2009 was 5.0 percent, compared with 2.7 percent for females. In the year ended 31 December 2009, the male population in the 80+ age group increased by 4.7 percent (2,600), to reach 57,300, while the female population increased by 2.2 percent (2,000), to 90,600.

Trends in the number of children (aged 0–14 years), 1969–2009

Trends in the number of children (aged 0–14 years) mainly reflect changes in the number of births. Changes in the number of children aged under 15 years impact directly on planning and policy making. The opening of new schools, the closing of existing schools, and the provision for school teachers, are all dependent on the number of children both now and in the future.

 Graph, Trends in the number and proportion of children 1969–2009.

In 1969 the population aged 0–14 years was 901,000, this rose to 937,300 in 1974. The number of children then fell to a low of 775,900 in 1988. Between 1989 and 2004 the child population increased again, to reach 891,500, and has remained steady at around 890,000 since then.

Although the number of children has fluctuated over the 40 years ended 31 December 2009, the proportion of children in the total population has declined steadily. The proportion of children has dropped as a result of declining birth rates and increased life expectancy. Children made up 32.1 percent of the population in 1969 compared with just 20.5 percent in 2009.

 At 31 December Number of children  Children as a proportion of total population (%)
Estimated de facto population
 1969 901,000  32.1 
 1979  864,500 27.3
 1989  776,500 23.0
Estimated resident population
 1999  878,200 22.8
 2009 892,600 20.5
In 2009, for every 100 girls under 15 years, there were 105 boys. This imbalance reflects the fact that more boys than girls are born each year, and although death rates are higher among boys, females do not begin to outnumber males until the age of 26.
Latest (2009-base) official projections (series 5) indicate that the number of children in New Zealand will increase only slightly. As a proportion of the total population, children are likely to decline to 18 percent in 2031, and 17 percent in 2061. From a planning perspective, changes at the subnational level will be particularly important. Those areas with higher fertility, net migration inflow, or a younger population, are likely to have a higher demand for education services than those areas containing older populations.

Population clock

Statistics NZ's online population clock gives a real-time approximation of the estimated resident population of New Zealand. The population clock uses the latest quarterly estimated resident population, and estimates for the expected number of births, deaths, and net migration during the following quarter. The settings for each component (births, deaths, and net migration) are derived by converting the quarterly estimated totals into a 'per minute' figure, making allowance for the number of days per quarter. The population clock can be viewed on the Statistics NZ website:

Different population measures

Users of population statistics need to be aware that there are three main population measures produced by Statistics NZ: the census night population count, the census usually resident population count, and the estimated resident population. The population counts published from the census are not comparable with the estimated resident population. The estimated resident population includes adjustments for net census undercount and for New Zealand residents temporarily overseas on census night. For more information see the 'Technical notes' section of this release.

For technical information contact:
Joel Watkins or Esther Hogenhout
Christchurch 03 964 8700

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National Population Estimates: March 2010 quarter will be released on 14 May 2010.