Background
This release contains estimates of the total population of New Zealand at 31 March 2010. 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 group and sex. 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 March 2010 quarter. Final estimates will be released on 13 August 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 analyses the median age of the population aged 65 years and over (65+). Previous releases have included special topics on trends in the number of children (0–14 years) between 1969 and 2009, 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 March 2010
The estimated resident population of New Zealand was 4,362,000 at 31 March 2010, comprising 2,141,700 males and 2,220,300 females. At 31 March 2010, there were 96 males for every 100 females.
Annual population change
In the March 2010 year, the estimated resident population grew by 56,300 (1.3 percent), compared with 42,200 (1.0 percent) in the previous March year. The population growth in the March 2010 year was higher than the average annual increase of 50,600 (1.2 percent) recorded during the 10-year period to March 2010, and the highest growth for a March year since 2004, when it was 65,400 (1.6 percent).
The population growth for the March 2010 year resulted from a natural increase (excess of births over deaths) of 35,300 and a net permanent and long-term (PLT) migration gain of 21,000, and was higher than recent years largely because of a drop in PLT departures. The level of net PLT migration was the highest for a March year since 2004 (28,000).
Historically, natural increase has been the dominant component of population growth. Over the last 40 years, natural increase accounted for four-fifths of New Zealand's total population growth. During the March 2010 year, natural increase accounted for a little over three-fifths of population growth.
Quarterly population change
During the March 2010 quarter, New Zealand's estimated resident population grew by 14,800 (0.3 percent). This growth resulted from a natural increase of 10,000 and a net PLT migration gain of 4,800. In comparison, for the March 2009 quarter, natural increase was lower at 9,100 while net migration was higher at 5,100, resulting in a quarterly population growth of 14,200 (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 March 2010, 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. The median age for males is now 35.5 years, while for females it is 37.5 years. The lower median age for males largely reflects their lower life expectancy of 78.4 years, compared with 82.4 years for females (New Zealand abridged life table, 2007–09). Latest national population projections (2009 base–2061 update) indicate that the median age will be 43.5 years in 2061 (series 5).
Median age of the population aged 65 years and over
The median age of the population aged 65 years and over (65+) was 73.3 at 31 March 1996 and rose to 74.2 in 2005 before dropping to 73.8 years at 31 March 2010. In the long term, the rising median age of the older population reflects the increasing number of people in the oldest age groups. In the short term, however, the median age of the 65+ population has dropped, which reflects the growth in the 65–69 year age group. The median age of the male 65+ population is 73.1 years, up from 72.3 years in 1996. The female population aged 65+ had a median age of 74.5 years at 31 March 2010, up from 74.2 years in 1996.
In 1996 there were 428,900 people aged 65+. Of these, 2.7 percent were aged 90 years and over (11,600). At 31 March 2010, 3.9 percent of the population aged 65+ (564,500) were aged 90 years and over (21,900).
Changes in age composition
The age composition of New Zealand's population has changed over the past decade. In the 10 years ended 31 March 2010, the number of children (aged 0–14 years) grew to 894,400, an average annual increase of 1,600 (0.2 percent). For the year ended 31 March 2010, the increase of 4,000 (0.4 percent) in the number of children was above the annual average for the decade. At 31 March 2010, children accounted for 21 percent of the New Zealand population, down from 23 percent at 31 March 2000.
At 31 March 2010, the population aged 15–39 years remained the largest population group, accounting for 34 percent of the New Zealand population, down from 36 percent a decade earlier. This age group reached 1,498,400, an increase of 14,200 (1.0 percent) compared with the March 2009 figure. In the 10 years ended March 2010, the average annual increase for this age group was lower, at 9,100 (0.6 percent).
The population aged 40–64 also remained a large proportion of the population, increasing from 29 percent to 32 percent in the decade ended 31 March 2010. This age group increased by 22,500 (1.6 percent) in the year ended 31 March 2010, to reach 1,404,700. This was below the average annual increase of 28,700 (2.3 percent) for the 10 years ended March 2010.
The proportion of the population aged 65–79 years was 9.5 percent at 31 March 2010, up from 9.0 percent in 2000. During the March 2010 year, the population aged 65–79 years increased by 2.7 percent (10,800) to reach 414,900. In the 10 years ended March 2010, the population aged 65–79 years grew at an average annual rate of 1.8 percent (6,900).
In the 10 years ended March 2010, there was also an increase in the proportion of the population aged 80 years and over (80+), from 2.8 percent to 3.4 percent. The 80+ population reached 149,600 at 31 March 2010, an average annual increase of 3.5 percent (4,300) 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 March 2010 was 4.9 percent, compared with 2.7 percent for females. In the year ended 31 March 2010, the male population in the 80+ age group increased by 4.7 percent (2,600), to reach 58,200, while the female population increased by 2.3 percent (2,100), to 91,400.
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: www.stats.govt.nz.
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
Email: demography@stats.govt.nz
Next release...
National Population Estimates: June 2010 quarter will be released on 13 August 2010.