12-Mo Avg of an Average Turn Around Time

[xarapre7]

I'm trying to get the 12-Mo Average of the average turn around time using the expression:

=Num(rangesum(above(Avg({$<[Group]={'AME'}>}[Working Days])),0,12),00) but, it's not giving the expected result as below.

Month	Average Turn Around Days	12-Mo Avg	Expected  12-Mo Avg
Jan-2015	9	12
Feb-2015	9	21
Mar-2015	9	21
Apr-2015	9	21
May-2015	7	21
Jun-2015	9	19
Jul-2015	7	21
Aug-2015	7	19
Sep-2015	9	19
Oct-2015	14	21
Nov-2015	11	26
Dec-2015	10	23	9
Jan-2016	9	22	9
Feb-2016	9	21	9
Mar-2016	10	21	9
Apr-2016	13	22	10
May-2016	14	25	10
Jun-2016	15	26	11
Jul-2016	15	27	11
Aug-2016	11	27	12
Sep-2016	11	23	12

Can you please help me with the correct expression to get the expected 12-Mo Average? This is actually getting the Average of an Average which is what i need.  Any help you could help is highly appreciated.  Thank you.

[sunny_talwar]

May be try RangeAvg() instead of RangeSum

=Num(RangeAvg(Above(Avg({$<[Group]={'AME'}>}[Working Days])), 0, 12), '00')

[xarapre7]

It works as expected.  Thanks!

[sunny_talwar]

May be this if you only want to see the numbers starting Dec-2015

=If(RowNo() > 11, Num(RangeAvg(Above(Avg([Average Turn Around Days]), 0, 12)), '00'))