SSRS Row visibility

Hi, please see the attachment of my table. I may need your help on the row "Trending % " visibility.
In this table, there are a few expressions
1) 1st column - 1st row: if it is a current month (not a full month), the field will show * with monthname. i.e. April *
=iif (monthname(month(today()))= Fields!MonthName.Value, Fields!MonthName.Value+"*", Fields!MonthName.Value)

2)2nd, 3rd, 4th, 5th column - 2nd row: it calculates the tranding % from first month and the second month.
i.e.
=(Last(Fields!Deal.Value)-First(Fields!Deal.Value))/First(Fields!Deal.Value)

3)5th column - 1st row: lookup function from 2 datasets
=Lookup(Fields!MonthName.Value,Fields!MonthName.Value,Fields!UniqueDeals.Value, "UniqueOpportunity")

What I need to do :
I want to hide trending % row when it is not a full month, since the calculation does not make any sense. As you see -86.49% is based on a partial April data.

I still want to show trending % row when 2 months are full month, since the calculation is reasonable. i.e. February , March.

Many Thanks!
Capture.JPG