Pivot Table & Percentage Column

Hi i'm trying to produce a pivot table that will show % of cancelled appointments.

There are different reasons codes for cancellations and i wish to show these in the pivot. I want to then show the % of cancelled appts (sum of the reasons) vs. the total of all appts (both completed and cancelled.

I have created 2 new calculated fields to get the sum of the cancelled and the sum of all columns. i wish to have the grand total field to show the %. I can add another field to work this out but the grand total field is giving me a whacky % at the bottom. im unsure of where to go from here and have searched but can seem to find any "clear" instructiuons

yeah sure

Appointments Data.xls

Ok, i see that is the case, so is there a simple course of action that can be taking to achieve the result im after? Can you simply show a column which does the calculation without the needt to add in any addition data?

I tried doing a formula for each row but when the filter is changed the formula doesnt calculate

basicallt im trying to workout the % ttoal of cancelations.

So the sum of Column B, C & D divided by the grand total to give me the percentage