The number of New Zealanders aged over 85 has more than trebled in the last three decades as New Zealand is getting older, according to Statistics New Zealand.
Men were the winners in the latest figures. In September 1978 there were 18,500 people over the age of 85,with 39 males per 100 females.
This year there were 63,900 in that age bracket, with the ratio of males increased to 49 per 100.
Government statistician Geoff Bascand said the increase in ratio was because male longevity increased more than female longevity.
New Zealand, along with other OECD countries, has an ageing population because of low fertility and low mortality, he said.
The rate of population growth was highest in the 65 years and over group, at 2.1 per cent.
The 15 to 64 age group grew at 1 per cent and the number of children aged up to 14 increased by just 0.1 per cent.
The figures for the last 10 years are even more marked, with over 65s increasing by 22.1 per cent, 15 to 64 by 13.9 per cent, and under 14s by 1.5 per cent.
In September the median age of New Zealanders was 36.4 years, compared with 33.7 a decade ago.
Men have a life expectancy of 78 years and women 82.2.
Latest Statistics NZ figures also show that New Zealand's resident population rose to 4.28 million at the end of September - mostly driven by an increase in the number of babies.
The population increased by 40,100, or 0.9 per cent, in the September 2008 year, down from 43,300, or 1 per cent, from the previous year.
The main contributor came from the natural increase, where 35,700 more people were born than died, which was 700 down on the previous year.
A fall in net migration was the reason behind the slowing population growth.
This year permanent and long-term arrivals exceeded departures by 4400, compared with 8300 the year before.
