Not able to perform Cumulative sum

[sandeepk21]

I am having data like below

Date  Quantity

Jan-2016   115000

Dec-2015   -95000

If I select Dec, 2015 then Sum must be -95000
and when I select Jan, 2016 sum must be 20000 and so on

Can I achieve this in expression? as I Tried TOTAL and Rangesum but it is not working, Kindly Help to achieve this