Pivot Table - Computation of Ratio of Subcategory

[Sarmie_Akintona]

I am new to Qlik and would appreciate any help. I have the table as shown below.

I wish to compute a new column as shown below:

In essence, I want the new column to have Amount of the SubCategory Field divided by the total of the respective Category. Something like Amount(AA)/Sum(A), Amount(AAA)/Sum(A), Amount(AAAA)/Sum(A), Amount(BB)/Sum(B), Amount(BBB)/Sum(B), Amount(BBBB)/Sum(B), etc

I will appreciate any kind assistance

[Sarmie_Akintona]

For future reference: Was able to fix it using the chart script: 

Sum({<[SubCategory]=>}Amount)/Sum({<[Category]=>} Total<Category> Amount)