Value will be always calculated for last 12 months from the current selection today date and 1st history date.
Let us take an example, if the first transaction had been taken place on 1st January 2013 and we are calculating it in current month it should be calculated as below
Month Name
Jan 13
Feb 13
Mar 13
Apr 13
May 13
Value
10
0
5
0
20
In current month, Value will be sum of all month value and divided by the number of months passed.
