The average net worth is the sum of all the personal wealth in the group, divided by the total number of households in the group. (moneysense.ca)
The more affluent a city was, the more likely it is to have a high number of households with rewards cards. (valuepenguin.com)
For example, the aggregate expenditures per household is the ratio of the total expenditures in each category to the total number of households in the category. (eia.gov)