Select a column, then select Results--> Grouping and Aggregation--> Cumulative Sum to display the values in the column as a cumulative sum, which is a rolling sum. Each value is added to the value in the row below it. A cumulative summary is presented at the end.
For example, here is a list of values:
18357.50 18171.25 17506.75 ========= 54,035.50
Results from a cumulative sum of these values are:
18357.50 36528.75 54035.50 ========== 108,921.75