sorry,

you have to remove the second "13-"

=SUMPRODUCT(--($A$2:$A$11=$F2)*(YEAR($B$2:$B$11)=G$1)*(13-MONTH($B$2:$B$11))*($D$2:$D$11))
+SUMPRODUCT(--($A$2:$A$11=$F2)*(YEAR($C$2:$C$11)=G$1)*(MONTH($C$ 2:$C$11))*($D$2:$D$11))


--
isabelle


Le 2011-11-17 09:39, isabelle a écrit :
hi,

create a new table
F2: F5 put the values €‹€‹(A, B, C, D)
G1: Q1 put the values €‹€‹(2011, 2012, 2013, etc ...)
in cell G2 put the following formula:

=SUMPRODUCT(--($A$2:$A$11=$F2)*(YEAR($B$2:$B$11)=G$1)*(13-MONTH($B$2:$B$11))*($D$2:$D$11))
+SUMPRODUCT(--($A$2:$A$11=$F2)*(YEAR($C$2:$C$11)=G$1)*(13-MONTH($C$2:$C$11))*($D$2:$D$11))

and copy this formula in range G2:Q5