Hello cbro4 and Welcome to Excel Forum.
To attempt to understand, there are three distinct Row ID's for Data Group 3 Data 3. Of those three distinct Row ID's 1 has a IsRelevant value of 100 and the other 2 have IsRelevant values of zero, so the percentage should be 33%.
Is that correct and if not please tell us the correct percentage along with an explanation of how it is calculated.