There are two main possibilities to aggregate series:
1. Aggregate analysis
Specify the period over which you want to aggregate the series. You also have the option of making this a rolling sum.
Sums up all values from the start of the series.
Sums up values of a series on a yearly basis.
Sums up all values of a series. The output is a single figure, the total sum.
Sums up series over a rolling window.
For more information see: