Pivot - Calculating ratio from grand total by categories

Hello everyone,

I hope I can rely on your help for this one - see this data set as an example:

Year Category Samplesize Defects
2022 A 10 1
2022 A 10 1
2022 A 10
2022 A 10
2022 A 10
2022 B 10 1
2022 B 10
2022 B 10
2022 B 10
2022 B 10


When I generate a new calculated field (Defect/Samplesize) to calculate the ratio of defects, the result will be 0.03 for a grand total.
However, if I add the categories into this, the calculation is performed for each category separately resulting in 0.04 for A and 0.02 for B:

Ratio Column Labels
Row Labels A B Grand Total
2022 0.04 0.02 0.03

What I actually want to calculate is the ratio of defects to the overall samplesize. The result I want would be 0.02 for A and 0.01 for B in this example.

Can you please help me to get excel to do this?


Kind regards,
Messiah

PS: I am sorry. Here is the link to the file of aboves example:
Example for Excelforum.xlsx