Using sieve readings in summary graphic table

I created a summary graphic table that references multiple lab data tables. One of the columns is:

<<IIf(<<SV READINGS.Reading>><=0.075,<<SV READINGS.Percent_Finer>>%)>>

"Dependent data" is checked.

However, I get a row for every sieve reading, even if it's blank. How do I get only the rows that I want?