Hard to establish this figure, but might be worth having a stab at it by working out what proportion of the population hold a passport. read more
The New Zealand population at the time, 2013 census, was 4,242,048. But you have to take into account that around 800,000 New Zealanders live overseas permanently and would hold a passport, but not be counted in the census. On the other hand people would have been overseas before that 5 year time period and not held a passport subsequently. read more