st: Series - Variations between 2 dates

["Luigino Ianni" <luiginoianni@hotmail.it>]

Dear All,

I’ m trying to solve the following problem:

Date 1.    Y= (A+B+C)/(D+E+F)
Date 2.    Y= (A+B+C)/(D+E+F)

How can I perform an analysis to measure the contribution of each element 
(A, B, C, D, E, F) to the variations in Y between the dates one and two?

Thanks in advance,

Luigino 

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