Decile Analysis compare with last year

[eddywong71]

Hi All,

I am using this set expression for current year and last year

=Aggr(
Ceil(Rank(Sum($Profit),4,1) / count($DISTINCT TOTAL Customer), 0.1) * 10
, Customer) 

Last year

=Aggr(
Ceil(Rank(Sum($Profit_Last_Year),4,1) / count($DISTINCT TOTAL Customer), 0.1) * 10
, Customer)

 Table as below

However, I want create a two column on Past 12 Month. Upgrade and downgrade for example select 20% from Past 12 Month. Upgrade =  138+.....+24 and Downgrade = 119. How can I create a set expression for Upgrade and downgrade.

Can anyone help ?