Median age of women having abortions in New Zealand

Median: Half of those women having an abortion are younger and half are older than this age.
Total abortion rate: The average number of abortions that 1,000 women would have during their life if they experienced the age-specific abortion rates of a given period (usually a year). It excludes the effect of mortality.

Abortion: Foetal loss excluding stillbirths, usually during the first 20 weeks of gestation. Induced abortions are those initiated voluntarily with the intention of terminating a pregnancy. All other abortions are called spontaneous, even if an external cause is involved such as injury or high fever.
All abortion statistics and derived abortion rates released by Stats NZ are based on the number of legally induced abortions. No information is available on spontaneous or illegal abortion.

Abortion rate: The proportion of women who have an abortion in a given year. Abortion rates from 1991 onwards are based on the mean estimated resident population. Before 1991, abortion rates are based on the mean estimated de facto population.
Abortion ratio: The proportion of pregnancies terminated by induced abortions. From 2007, Stats NZ's standard for abortion ratios is the number of induced abortions per 1,000 known pregnancies (live births, stillbirths and induced abortions combined).
Total abortion rate: The average number of abortions that a woman would have during her life if she experienced the age-specific abortion rates of a given period (usually a year). It excludes the effect of mortality.

http://datainfoplus.stats.govt.nz/Item/nz.govt.stats/7845b64a-dc1a-427c-b9a5-89eaf7c4580b#/nz.govt.stats/7845b64a-dc1a-427c-b9a5-89eaf7c4580b/25

While the data is collected for 'women' it is important to note that it actually includes all people who had an abortion, and that the data may include some transgender people.

For 2004–08 health domicile codes are based on the 2001 health domicile classification (this is based on the 2001 area unit classification). From 2009 health domicile codes are based on the 2006 health domicile classification (this is based on the 2006 area unit classification - 2006 boundaries are only used from 2009 because MOH did not release their 2006 version until July 2008).

At the URL provided, download 'Abortion statistics: Year ended December 2019' file.

Abortion statistics measure the number of induced abortions that occur in New Zealand hospitals or licensed abortion clinics.

For every induced abortion carried out in New Zealand, as approved under the Contraception, Sterilisation and Abortion Act 1977, an ASC Form No. 4 (Notification of Abortion) must be completed and forwarded to the Abortion Supervisory Committee (ASC) within one month of the abortion.
An abortion may only be performed in an institution licensed by the Abortion Supervisory Committee for this purpose.
The hospital or clinic send the completed ASC Form No 4 to the Tribunals Unit (a division of the Ministry of Justice). The Tribunals Unit provides the ASC with administrative services. The forms are then sent to Stats NZ who collates abortions data based on information from the notification form. Errors or omissions are referred back to the Tribunals Unit who liaises with the hospital or clinic. When Stats NZ has finished processing the forms they are returned to the Tribunals Unit.