'Age' refers to the age of a person (or subject) of interest at last birthday (or relative to a specified, well-defined reference date).
Primary household maintainer: First person in the household identified as someone who pays the rent or the mortgage, or the taxes, or the electricity bill, and so on, for the dwelling. In the case of a household where two or more people are listed as household maintainers, the first person listed is chosen as the primary household maintainer.
The order of the persons in a household is determined by the order in which the respondent lists the persons on the questionnaire. Generally, an adult is listed first followed, if applicable, by that person's spouse or common-law partner and by their children. The order does not necessarily correspond to the proportion of household payments made by the person.