The size and composition of this type of household has changed little since the late 1970s. In 2000, 42% of households comprised 2 or more adults and no children aged less than 16.

The proportion of households consisting of a married or cohabiting couple with no children of any age has remained stable at around 28% from the late 1970s to 2000, as has the proportion of households containing two or more unrelated adults (3% in 2000). The proportion of households consisting of a married or cohabiting couple with adult (non-dependent) children only has varied slightly over this time but remained consistently at 6% since the mid 1990s.