That's a good point and I have done that in the past (for NZ). Household size has remained steady over roughly the same period (decade up to 2018 where census d

That's a good point and I have done that in the past (for NZ). Household size has remained steady over roughly the same period (decade up to 2018 where census data is available). This doesn't account for a possible significant change in household size distribution of course (e.g. the possibility of many more elderly living alone while young people increasingly live in shared housing).