New Zealand has a large number of islands.
The two main islands, which are much larger than the rest and where nearly all of the population lives, are the North Island and the South Island. The latter is often referred to as the "mainland", especially by its residents, despite it being only a little larger and having a lower population.
The following is a list of many of the islands of New Zealand:
... from 18 to 24, 33.6% from 25 to 44, 20.6% from 45 to 64, and 9.6% who are 65 years of age or older. The median age is 35 years. For every 100 females there are 96.9 ...