=SI(ESTERREUR(MOYENNE(SI((Data2011!$A$2:$A$1000<>"TOTN" )*((GAUCHE(Data2011!$A$2:$A$1000;3)=LOSbyRateCodebyMonth!$A32)+(GAUCHE(Data2011!$A$2:$A$1000;2)=LOSbyRateCodebyMonth!$A33))*(MOIS(Data2011!$C$2:$C$1000)=3);Data2011!$F$2:$F$1000)));0;MOYENNE(SI((Data2011!$A$2:$A$1000<>"TOTN" )*((GAUCHE(Data2011!$A$2:$A$1000;3)=LOSbyRateCodebyMonth!$A32)+(GAUCHE(Data2011!$A$2:$A$1000;2)=LOSbyRateCodebyMonth!$A33))*(MOIS(Data2011!$C$2:$C$1000)=3);Data2011!$F$2:$F$1000)))