accumulated amount value between 2 months

[CognosVN]

I'd accumulated amount between 2 values ​​(for example, 6/2011 to 5/2012) in the first column (A) and 1 is the value amount of the previous year (B) (6/2010 to 5/2011) and 1column is an A / B!
please suggest me solutions or rational function
thanks and rgds.

[blom0344]

It is called a division and it merely involves defining the quotient of the 2 dataitems, or if you want to put it into 1 expression:

total(case when [somedate] between .... and .... then [somevalue] else 0 end) /
total(case when [somedate] between .... and .... then [somevalue] else 0 end)

set the aggregate type of this dataitem to calculated..