Overview of age groups, including by ethnicity, and life expectancy.

Median Age

Christchurch City's median age was 38 years in 2013. This has been steadily increasing since 1996.

By 2043, the median age is projected to increase to 42.6 years (slightly lower than the projected New Zealand median age of 43 years).

Chart showing median age comparing Christchurch and New Zealand

Median Age, 1996-2043


Waimakariri and Selwyn districts

Neighbouring Waimakariri District has a slightly older population overall than Christchurch (median age for Waimakariri was 42.6 years in 2013) and is projected to remain higher than Christchurch City's by 2043, reaching a median age of 47.6 years.

Selwyn District has a similar aged population to Christchurch (median age for Selwyn was 38.2 years in 2013) and is projected to be slightly lower than Christchurch City's by 2043, reaching 41.6 years.


Differences within the city (2013)

In 2013, the parts of the city with the highest median ages were located in Banks Peninsula, where each area unit had a median age of at least 45 years. Akaroa had the city's highest median age at 56.2 years. The area units spanning across the Port Hills all had median ages of at least 40 years.

The city's lowest median ages were located close to the university (Ilam had the city's lowest median age at 22.9 years), followed by Riccarton West, Upper Riccarton and Riccarton.

Area Unit (suburb) map of median age, 2013

Median Age by Area Unit (suburb), 2013

Age Groups

The number of older people aged over 65 years is projected to more than double between 2013 and 2043, increasing from 52,100 to 105,700.

Meanwhile, as a proportion of the total population, the 65 years and over age group will increase from 15% to 23%. 

The number of people in the working age group (15 to 64 years) is projected to increase from 240,600 to 284,000 between 2013 and 2043. As a proportion of the total population, the working age group is projected to decrease from 67% to 62%.

The number of children (aged under 15 years) is projected to slightly increase to from 64,000 in 2013 to 69,400 by 2043. However, as a proportion of the total population, this cohort will decrease from 18% of the population to 15%. 

Information about the age structure of a population is important as it has implications for the provision of appropriate services such as housing, healthcare and education.

  • View Excel table [XLSX, 24 KB] [Excel 25KB] containing the most recent population projections by age for Christchurch City.
Population pyramid by gender, 2013 and 2043

Population pyramid by gender, 2013 and 2043

 

chart of 5-yearly age groups, 2001 to 2043

Age groups (5 yearly), 2001-2043

Child : Older Person Ratio

The Child : Older Persons ratio has decreased from 1.5 children for every 1 older person in 1996, to 1.2 children in 2013. This ratio is projected to decrease further, reaching 0.7 children for every 1 older person by 2043.

The Child : Older Persons ratio is a measure of the composition of the portion of the population that is made up of ‘dependents’: those who are typically too young and those who are typically too old to work. This is expressed as the number of children aged 0-14 years, divided by the number of those aged 65 years and over. A decreasing Child : Older Persons ratio illustrates a shift in type of dependents, from more children to more older people.

By 2023, the balance of dependents is projected to shift, so that those aged over 65 years will make up a greater proportion of the population than those aged 0-14 years.

Child : Older Persons Ratio

Child : Older Persons Ratio, 1996-2043

 

This ratio is a crude measure and does not take into account ‘dependents’ aged under 15 years or aged 65 years and over who may be active in the workforce, or conversely, the varied nature of employment undertaken by those aged 15 to 64 years.

Dependency Ratio

For every 100 people of working age, there were 48 dependents in 2013. This will increase rapidly over the next 30 years, reaching 62 dependents per 100 people of working age by 2043.

The Dependency Ratio is a measure of the balance between dependents (those who are typically too young or too old to work) and those of working age in the city's population.

The ratio is expressed as the combined number of people aged 0 to 14 years and people aged 65 years and over (‘non-working age’ population), divided by those aged 15 to 64 years (the ‘working age’ population).

A rising dependency ratio illustrates an increasing imbalance in the size of the non-working population dependents) versus the working population, and gives an indication of the burden on those of working age to provide for those who are typically not of working age.

Dependency Ratio

Dependency Ratio, 1996-2043


This ratio is a crude measure and does not take into account ‘dependents’ aged under 15 years or aged 65 years and over who may be active in the workforce, or conversely, the varied nature of employment undertaken by those aged 15 to 64 years.

Life Expectancy

For a baby girl born in 2013, the average life expectancy was 83.1 years. For a baby boy, this figure was 79.4 years.

Historic and projected life expectancy in Christchurch closely mirror that of the whole of New Zealand. Life expectancy at birth has increased for both males and females over time, and the gap between the sexes has narrowed in recent years.

In 1996, life expectancy at birth for Christchurch males was 74.8 years, compared with 80.3 years for females- a difference of 5.5 years.

By 2013 the gap had decreased to 3.6 years, and by 2043 the gap is projected to be 2.9 years. By 2043, a new born male is projected to have a life expectancy of 85.1 years, while for a new born female this figure is 88 years.

Chart showing life expectancy by gender, 1996-2043

Life Expectancy by Sex, 1996-2043

 

Ethnic Age Differences and Population Pyramids

Overall, the city’s age-sex structure is very different between the four major ethnic groups, for both 2013 and 2038.

Median Age by Ethnicity

The European or 'Other' ethnic group is the only group with a higher median age than the city's overall median age, and will continue this trend over the next 25 years. The median age of this ethnic group was 39.8 years in 2013, and is projected to be 43 years by 2038.

The Maori and Asian ethnic groups will have a very slight increases in median age for each inter-census period: Maori will increase from 23.8 years to 27.3 years between 2013 and 2038, whereas the Asian ethnic group will increase from 30.6 years to 32.8 years.

The Pacific ethnic group, which has an overall median age increase from 22.9 years to 23.6 years between 2013 and 2038, will have a 10 year period where the median age decreases slightly, before increasing from 2023 onwards.

chart of median age by ethnicity

Median age by ethnic group, 1996-2038

European Structure

The European or 'Other' ethnic group is older and ageing, as shown by the 'bulge' in the middle and upper parts of the pyramid in 2013 and the large numbers aged 50 years and over by 2038. This ethnic group has, and will continue to have, the lowest fertility rates out of all ethnic groups. The European or 'Other' ethnic group will experience a decrease in the number of children and younger adults (a combined decrease of 11,000 aged under 25 years) between 2013 and 2038; the only ethnic group to do so.

European Population Pyramid by Gender, 2013 and 2038

European or 'Other' population pyramid by gender, 2013 and 2038

Maori and Pacific Structure

The age-sex structure of both the Maori and Pacific ethnic groups is very similar. The structures resemble a typical 'pyramid', indicating a relatively youthful population, with fewer older people. The age structure will continue to be very pyramid-like by 2038. The Pacific ethnic group especially will continue to have large increases in the under 25 year age groups. These two ethnic groups have, and will continue to have, the highest fertility rates and lowest life expectancies out of all ethnic groups.

Pacific Pyramid

Pacific population pyramid by gender, 2013 and 2038

Maori Population Pyramid

Maori population pyramid by gender, 2013 and 2038 

Asian Structure

The Asian age-sex structure is largely a reflection of immigration policy since the 1990s, which favours younger to middle aged immigrants who can contribute to the economy. This age structure also reflects the large number of young Asian students who come to Christchurch to study. This ethnic group is ageing (it has the longest life expectancy out of all ethnic groups for each inter-census period), however there is also a large amount of growth in the population aged under 15 years.

Asian population pyramid

Asian population pyramid by gender, 2013 and 2038

Information about data used

Median age:

The median age is the point at which half the population is older and half is younger. Changes in the median age of a population indicates whether the overall age distribution of residents is changing. Information about the structure of a population is important as it has implications for the provision of appropriate services such as housing, healthcare and education. Christchurch's median age is expected to increase due to the large post-World War Two birth cohort (the Baby Boomers) reaching older ages, lower birth rates due to couples delaying or deciding not to have children, and increased life expectancy, due to medical advances and improvements in overall quality of life.

The projections do not take into account non-demographic factors (eg war, catastrophes, major government and business decisions) which may invalidate the projections.

Note: This time series is irregular. Because the 2011 Census was cancelled after the Canterbury earthquake on 22 February 2011, the gap between this census and the last one is seven years. The change in the data between 2006 and 2013 may be greater than in the usual five-year gap between censuses. Be careful when comparing trends.

Sources: Statistics New Zealand, 2013 Census of Population and Dwellings (external link)  and Subnational Population Projections, 2013(base)-2043 update (external link)  

Age cohorts:

Christchurch's median age is expected to increase due to the large post-World War Two birth cohort (the Baby Boomers) reaching older ages, lower birth rates due to couples delaying or deciding not to have children, and increased life expectancy, due to medical advances and improvements in overall quality of life.

The projections do not take into account non-demographic factors (eg war, catastrophes, major government and business decisions) which may invalidate the projections.

Source: Statistics New Zealand, Subnational Population Projections, 2013(base)-2043 update (external link)  

Life expectancy:

A summary measure of the death and survival rates of the population. The average length of life of a newborn baby, assuming they experience the age-specific mortality rates of that year throughout their life. Data is provided for males and females.

The data used to construct the 2012–14 subnational life tables comprises: 1. Deaths registered in New Zealand of people resident in New Zealand in the December years 2005–07 and 2012–14, respectively, by date of death, date of birth, sex, ethnicity, and geographic area of usual residence. 2. The estimated resident population of New Zealand at 30 June 2006 and 2013, by single year of age, sex, ethnic group, and geographic area of usual residence.

Sources: Statistics New Zealand: Abridged Life Tables (external link) and Subnational Population Projections, 2013(base)-2043 update (external link)  

Ethnic population projections:

It is important to note that these ethnic populations are not mutually exclusive because people can and do identify with more than one ethnicity. People who identify with more than one ethnicity have been included in each ethnic population. The 'Maori', 'Pacific peoples', 'Asian', and 'Middle Eastern/Latin American/African' ethnic groups are defined in Level One of the Standard Classification of Ethnicity 2005. The projections for the 'European or Other (including New Zealander)' group include people who belong to the 'European' or 'Other ethnicity' groups defined in Level One of the standard classification. 

The projections are not predictions. The projections are designed to meet both short-term and long-term planning needs, but are not designed to be exact forecasts or to project specific annual variation. These projections are based on assumptions made about future fertility, paternity, mortality, migration, and inter-ethnic mobility patterns of the population. Although the assumptions are carefully formulated to represent future trends, they are subject to uncertainty. Therefore, the projections should be used as guidelines and an indication of the overall trend, rather than as exact forecasts.

Source: Statistics New Zealand, Subnational Ethnic Population Projections, 2013(base)-2038 (external link)