Pivot Table needs % of grand total column

Hello I have a table, as attached, that has been analysed with a pivot table that breaks down the number of PC vs PN for each ST in the table, and provides the sum of PC + PN for each ST. But I also need the % of each sum of PC + PN of the grand total. For example, from line 1, for ST 5, there are 3 PC and 0 PN that sum 3 PC + PN, and calculate to 4.68% of the total of 64 samples. I don't want 'sub-percentages' for PC and PN, just one more column in J that gives me the % of grand total for each total ST count.

you could add "ST" to Data Field a 2nd time, set to Count and show as % of Grand Total

the above will generate your required Grand Total % - e.g. 4.69%, 17.19% etc but also generate 2 other columns you likely don't want -- (% of PC, % of PN) -- there's no elegant way of handling these aside hiding / grouping (and collapsing) the columns.