To take those metrics is not easy. In the Netherlands there is a grid, like in Italy and other countries, so that you can monitor : in Italy the data are transported using TCAP over the copper cables, directly to the power grid controller. In the Netherlands data are collected in different ways, I was working time ago on a project of putting a simcard into the home counters, to collect the power consumed and the amount of gas being consumed.
Is not easy to have such a data without a grid controller.
I can imagine it is not easy to get to these type of metrics.
We are in the replacement process of the energy meters, installing so called intelligent meters, but this whole project just started and will take maybe even years before all meters are replaced. That tells me, more traditional methods are used to come to the figures as presented. I can imagine these figures are derived by the infrastructure outage support information; We can get more or less realtime information on power outage on zip-code level from them.