Expression for Index % across Time periods

Hi All,

7.3.0.2

We have setup custom Index -which provide us a % difference across time buckets.

I am hitting inconsistancy  in the Results

     -works for week and month but WK shows no data for Qtr.

     -Shows dta for some Product Lines but WK shows no data for other.

Please hekp to make the expression robust across periods and across Product Lines.

I suspect the server expression needs to be fixed. I have tried the AVG instread of SUM..Still the results are inconsistant

SERVER EXPRESSION

sum (nvl( (  (  ( branch_data.hyp_cost_of_sales - branch_data.hyp_cos_lm   )  /   ( branch_data.hyp_cost_of_sales )   )  * 100 ),0))