sales above or below averge per month

[HAmzehAF]

Hello,

im trying to use this 
sum(SALE)-(sum(total SALE))/count( total distinct Month)
to get this effect 

but im using a drilldown ( month - day ) 
how can i do it ??

im trying to do ( sales above or below averge per month ) 

[Chanty4u]

Try this

Sum(Sales) - Avg({<Month=>} TOTAL <Month> Sales)