An aggregate is the sum of the values for each of the elements in the universe. For example, aggregate household income is the sum of the incomes of all households in a given geographic area. Means are derived by dividing the aggregate by the appropriate universe. When an aggregate used as a numerator is rounded in the detailed (base) tables, the rounded value is used for the calculation of the mean.

To protect the confidentiality of responses, the aggregates shown in matrices for the list of subjects below are rounded. This means that the aggregates for these subjects, except for travel time to work, are rounded to the nearest hundred dollars. Unless special rounding rules apply (see below); $150 rounds up to $200; $149 rounds down to $100; $100 stays $100 unless otherwise noted. Note that each cell in a matrix is rounded individually. This means that an aggregate value shown for the United States may not necessarily be the sum total of the aggregate values in the matrices for the states. This also means that the cells in the aggregate matrices may not add to the total and/or subtotal lines.

Special rounding rules for aggregates.

-If the dollar value is -$99 through +$99, then the dollar value is rounded to $0.

-If the dollar value is less than -$100, then the dollar value is rounded to the nearest -$100.

-If the dollar value is $100 or -$100, do not change the value.

Aggregates Subject to Rounding:

Contract Rent, Rent Asked

Earnings in the Past 12 Months (Households)

Earnings in the Past 12 Months (Individuals)

Gross Rent*

Income Deficit in the Past 12 Months (Families)

Income Deficit in the Past 12 Months Per Family Member

Income Deficit in the Past 12 Months Per Unrelated Individual

Income in the Past 12 Months (Household/Family/Nonfamily Household)

Income in the Past 12 Months (Individuals)

Mobile Home Costs

Real Estate Taxes (Per $1,000 Value)

Rent Asked

Selected Monthly Owner Costs* by Mortgage Status Total Mortgage Payment Travel Time to Work**

Type of Income in the Past 12 Months (Households) Value, Price Asked

[*Note: Gross Rent and Selected Monthly Owner Costs include other aggregates that also are subject to rounding. For example, Gross Rent includes aggregates of payments for "contract rent" and the "costs of utilities and fuels." Selected Monthly Owner Costs includes aggregates of payments for "mortgages, deeds of trust, contracts to purchase, or similar debts on the property (including payments for the first mortgage, second mortgage, home equity loans, and other junior mortgages); real estate taxes; fire, hazard, and flood insurance on the property, and the costs of utilities and fuels."]

[**Note: Aggregate Travel Time to Work is zero if the aggregate is zero, is rounded to 4 minutes if the aggregate is 1 to 7 minutes, and is rounded to the nearest multiple of 5 minutes for all other values (if the aggregate is not already evenly divisible by 5).]