Example CSV output is shown below.

Output is presented wide, with each recorded variable in a separate column. Each new row, from Row 3 downwards, gives the observations for a different Entity ID. If there are N entities in a simulation at a given time, there will be N rows for that timestep. When those N rows have been recorded to the CSV, the Entity ID resets to 1 and the next timestep is recorded. Note that as entities enter and leave simulations continuously, N will vary. So, timesteps may have different numbers of rows from each other.