School leavers staying on at school until age 17 in New Zealand

Schools are assigned a decile based on socio-economic factors in the community from which schools draw their students. Decile 1 schools are the 10% of schools with the greatest proportion of students from the most socio-economically deprived areas. Decile 10 schools are the 10% of schools with the greatest proportion of students from the least socio-economically deprived areas.

Retention Rate: Percentage of students staying on at school to age 17.
School leavers: School leavers in 2025 are students that permanently left school to enter the workforce and/or undertake further education and training outside of the compulsory schooling system sometime between 1 March 2025 and the last day of February 2026 (inclusive). School leavers are identified using ENROL.

https://www2.nzqa.govt.nz/ncea/about-ncea/#e1158_heading1

Domestic students who were aged less than 19 in their first enrolment in ENROL; including alternative education students, students 16 or over on 1 March 2024 and students attending teen parent units.
Students with leave reason; 'end of schooling' or 'early leaving exemption'
Students with leave reason 'transferred to another school in New Zealand' or 'transferred to home schooling' but did not re-enrol in another school according to ENROL
Students with leave reason 'gone overseas permanently', who meet the age criteria
Students who attend for a period of time at the start of 2025 but leave before 1 March 2025 are counted with 2024 leavers.

Returning adult students (aged 19 or more) with a year gap in their attendance
Exchange and International fee-paying students
Students who successfully transferred to another school in New Zealand or to home schooling
Deceased students.

At URL provided, select 'Time series: School leavers retention to age 17 or above (2015-2025)' from 'Time Series Data' section.