When referencing non-archived webpages (webpages that are designed to change) in your work, you will need to include a retrieval date with the URL. To determine if a page is archived or non-archived, check for a permalink button. If a permalink is available, the page is archived and does not require a retrieval date.
The following resources require retrieval dates:
The example below shows how to include a retrieval date when required.
Reference list entry
StatsNZ. (2019, November 14). Estimated population of NZ. Retrieved 20 January, 2020, from https://www.stats.govt.nz/indicators/population-of-nz
StatsNZ (2019) shows that ... (para. 2).
... (StatsNZ, 2019, para. 2).