Keep only the last date in a tablix whith formula using previous

Hi,

I am using this formula in a tablix

=iif(Previous(Fields!Extract_Date.Value)="", "", (
(Fields!Percent_IPCoverage.Value-Previous(Fields!Percent_IPCoverage.Value))*1
+(Fields!Percent_DVerCoverage.Value-Previous(Fields!Percent_DVerCoverage.Value))*2
+(Fields!Percent_Formalized.Value-Previous(Fields!Percent_Formalized.Value))*2
+(Fields!Percent_Traced.Value-Previous(Fields!Percent_Traced.Value))*3
+(Fields!Percent_StakeholderValidation.Value-Previous(Fields!Percent_StakeholderValidation.Value))*3
+(Fields!Percent_Compliant.Value-Previous(Fields!Percent_Compliant.Value))*3
)
/(1+2+2+3+3+3)
)

I would only display the last Extract Date in my tablix and corresponding value.

How is it possible ?

Thanks in advance.