Good guess. Your interpretation is probably right.
To answer your question we neeed to know what it takes to make the top 10%. According to this site,
https://www.newshub.co.nz/home/money...ealanders.html
in 2020 it was $860,000.
That seems ridiculously low. Surely you'd need several million to make that list? I know a fair number of people with a net worth of several million, and the vast majority own no residential property other than their own home. Most of them certainly 'cut their teeth' on flats and/or houses but progressed to commercial and industrial investments. I'm sure that's common throughout the country.