Configure the Aggregation widget as follows:

1. Configure general parameters (see General widget settings).
   

2. Select the field to aggregate the data by (1).

3. If non-numeric fields are selected, then in the Aggregate op field, select count (2) -the number of events will be counted. If a numeric field is selected, then you can select the sum, average, minimum and maximum value.

   In the example on the image above, the widget shows the minimum age of a recognized person for each video camera.

   
   

4. Click Save.