The median age of a Wanganui resident is 42 years - four years older than the median age of a New Zealand resident.
This and other details from the 2013 census were teased out at a recent presentation in Wanganui.
Michael Berry and other staff from Statistics New Zealand made the presentation to a group of about 30 people including council staff, lawyers, business people and representatives from social agencies at the War Memorial Hall.
Mr Berry said the census had thrown up some interesting facts about New Zealand's population.
Since 1981, the median age had increased by 10 years, from 28 to 38. But in Wanganui the median age was higher still at 42 years.
"In Wanganui, we're seeing a real bulge in that middle-aged bracket, from the 40s to the 60s," Mr Berry said.
However, Wanganui's Maori population tells a different story - the median age is 24 years old.
"In the Maori population there are a lot more children and young people, but not as many older people," Mr Berry said.
Wanganui's cultural diversity was not as great as many other parts of the country.
The district has a much higher percentage of European/Pakeha and Maori people - 77 per cent and 21.7 per cent respectively, compared to the national figures of 74 per cent and 14.9 per cent. Only 11.9 per cent of Wanganui's population was born overseas compared to 25.2 per cent nationwide.
Wanganui's population at the 2013 census was 42,153, a decrease of 1.1 per cent from the 2006 census.
However, the number of houses had increased by 4 per cent since 2006, to 19,389.
Mr Berry said population models indicated that Wanganui's population would decline slightly and age significantly over the next few decades.
Mr Berry said he and his staff were in the middle of a nationwide census tour and would visit around 40 towns and cities.
"The purpose of our visit is obviously to present census data, but also to connect with our communities," he said.
Mr Berry said census data was not merely a set of dry, boring statistics - it could be used in many practical ways, he said.
"We heard of an example of census data being used in Stratford. There were people in Stratford trying to get the footpaths in the town improved, and they used census data to show that Stratford had a high percentage of elderly people, who were more likely to need good footpaths."
The first New Zealand census was held in 1851.