Mean and median household net worth in New Zealand

Median and mean values for assets and liabilities are for those who had that particular asset or liability.

Assets and liabilities held in a business or trust are excluded unless mentioned.
Figures may not sum to stated totals, due to rounding.
Estimates are suppressed for confidentiality and quality reasons if fewer than five households (10 for medians) contribute to the cell, or if sampling errors are 51 percent or greater.

Net worth: is the value of a person or household’s assets, minus their liabilities.
Assets: are something a person or household owns, such as property or investments.
Liability: is an obligation such as a debt, mortgage, or loan. The liability's holder is obliged, under specific circumstances, to provide a payment or series of payments to whomever they are liable to.
Household: is either one person who usually resides alone, or two or more people who usually reside together and share facilities (eg for eating or cooking) in a private dwelling. A household may contain one or more families, other people in addition to a family, or no families at all, such as unrelated people living together. Statistics New Zealand don't include non-private dwellings such as hostels, or the rest home and hospital sections of retirement homes (serviced apartments within retirement homes are counted as private dwellings).

http://www.stats.govt.nz/browse_for_stats/people_and_communities/Households/HouseholdNetWorthStatistics_HOTPYeJun15/Data%20Quality.aspx

At URL provided, select "Household Net Worth Statistics: Year ended June 2015 – tables" from the box to the right-hand side of the page.

The Net Worth Household Statistics were collected as a component of the Household Economic Survey. To capture asset and liability information in enough detail, Statistics New Zealand increased the sample size for Household Economic Survey 2014/15 from 5,000 to 8,000 households.
The survey is a sample survey that uses statistical weights to calculate income and expenditure estimates for the total New Zealand population. For Household Economic Survey 2014/15, they used the weights based on the Census 2013 population.
The target population for HES is the usually resident population of New Zealand living in private dwellings, aged 15 years and over.