@Sergei BaklanI have tried that option. It shows every source data value in the table as a % of the single Grand Total at the bottom right of the PivotTable. (The source data is not shown in my example.)
The values in the example are already "Show Values As: Running Total in Years".
I need to take that computed result and compute its percentage of the Grand Total for its same row.
@pwilson4500 , if creating the PivotTable you added your data to data model, you may create the measure to show running total in %. For maintenability better to split it on two, running total itself, like