Quantifying IAQ values of Bosch BME680

I have recently started working with BME680. I have gone through its data sheet and don’t quite understand how the IAQ index values are mapped. When we say an IAQ of 35 for eg, is there a way to determine the concentration of VOC’s at IAQ of 35?Can somebody please help me on this?

i dont have much idea about this. Maybe you are looking at the wrong place for the solution. If you having any issue with cayenne then i can help you.