• Data reference period
• Geographic localization (Cities/ metropolitan areas)

• HOUSEHOLD DWELLING :  Dwelling that is normally intended to accommodate only one family, on the condition that it is not being used for other purposes at the period of reference.
• HOUSEHOL DWELLING OF USUAL RESIDENCE:  Occupied household dwelling  that  is the usual or main residence of at least one household.
• RESIDENT POPULATION:  Set of persons who, regardless of being present or absent in a given housing unit at the moment of observation, have lived in the place of their usual residence for a continuous period of 12 months prior to the moment of observation, or have arrived to the place of their usual residence during the period of 12 months prior to the moment of observation, with the purpose of living there for a year, at least.
• REFERENCE PERIOD:  Period to which the information refers and which may be a specific day or a time interval (month, fiscal year, calendar year, among others).

(Resident population in housing units of usual residence with toilet and wastewater drainage system/ Resident population in housing units of usual residence)*100