Calculating running count based on conditions in WEBi

Hi All,

We are facing an issue to achieve one of the requirements in WEBi. I have created a small excel file based on my client requirement. And i need to implement the same in WEBi.We need to implement the logic in WEBi for Column D highlighted in yellow(Column E is a formula, referencing column D).

Can someone help me out with proper Variables how to achieve this in WEBi.

Help is really appreciated and points are awarded.

Thanks

Muralidhar