The answer does not really fit to the question as it is less about information missing or exlcuded but wondering how representations follow a certain logic. Especially if we consider smart metering as a next step, the question is how the average is calculated. For the presented average number of 128l per person per day, this seems like a statistic average; if smart meters are then combined with other data of a household, it is an aggregate based more in a predictive logic?