SSRS code not working properly

Hi

I am trying to use this code to calculate and give me a value representing a  percentage of LoggedTerritoryGoal.Value of a specific month. But it is not working I am getting the full LoggedTerritoryGoal.Value. can someone take a look at this and advice me.

=IIF(Month(Parameters!EndDate.Value) > MAX(Fields!MonthNmbr.Value),
(Fields!LoggedTerritoryGoal.Value / 12 * MAX(Fields!MonthNmbr.Value)),
(Fields!LoggedTerritoryGoal.Value / 12 * Month(Parameters!EndDate.Value))
)