Need quick help to calculate percentage in Report Analyzer

I have the following data:

Student_name Subjects Marks %
John Maths 60 60% (60/100)*100)
Science 30 30%
Social 10 10%


This is the general approach to calculate the percentage and the same is working on Pentaho Report analyzer tool with this data.

But when I filter out to select only two subjects (Maths, Science) then the percentage is calculating as:

Maths 60 66.6%
Science 30 33.3%

It is calculating the percentage based on the distribution of selected values.

is it not possible to get same actual values as Maths: 60% and Science 30% if I deselect other values in Pentaho Report Analyzer?