Structural quanitites for compound walls and compound slabs

Hi

I've added  "Structural Quantities" to my walls and slabs as a catalog type definition. For walls it shows length, area and volume, but for my compound slab and compound walls it don't. Why is that?

Here a report created with the reports tool over elements in a file. Note that the wall on the last row is the compound wall with it's 3 leaves right above it, and neither the wall nor the leaves are displayed with the volumes. 

I'm a structural designer and it's a mess to report volumes when beams and columns are reported one way (Structural Quantities) and walls and slabs are reported another (Quantities). I just want one unified way to report all volumes. 

Robert