Simple % growth Cal SOS!

[damienm]

Help, can anyone provide me with the expression I would use to cal the % growth for the attached in a cal field.

I have built a crosstab with one measure (Retail Value) but with time periods and products running across and then by store. I tried the following but keep getting errors.

[Retail_Sales_DBR_Cube].[Fiscal Period].[YTD][Retail_Sales_DBR_Cube].[Measures].[Retail Value]/[Retail_Sales_DBR_Cube].[Fiscal Period].[Prior YTD][Retail_Sales_DBR_Cube].[Measures].[Retail Value]-1

I am very new to this and am completely lost at this stage, any help much appreciated!  Also need to cal the total too!

[ezgrand]

( [Retail_Sales_DBR_Cube].[Fiscal Period].[YTD][Retail_Sales_DBR_Cube].[Measures].[Retail Value] - [Retail_Sales_DBR_Cube].[Fiscal Period].[Prior YTD][Retail_Sales_DBR_Cube].[Measures].[Retail Value] ) / ([Retail_Sales_DBR_Cube].[Fiscal Period].[Prior YTD][Retail_Sales_DBR_Cube].[Measures].[Retail Value] ) * 100


(TY Sales - LY Sales) / (LY Sales) * 100