The weekly average for all of the Netherlands is calculated by adding up all the values measured in one week and dividing this by the number of measurements taken.
Number of measurement locations
Weekly number of sewage water treatment plants that have reported at least one measurement. The weekly average is calculated by taking the average of all measurements at these locations. This number can vary each week because not all measurements are successful.
Average number of virus particles per 100.000 inhabitants over time
Average number of virus particles per 100.000 inhabitants
This map shows the average number of virus particles per 100.000 inhabitants, per safety region. Please note: on the 26th of November the legend has been revised.