Hi ! 
I have 14 VOI and 50 subjects. I want to extract mean and SD of each VOI on each subject. 
With the Draw: descriptives function I have these information 3 times:

VOI nvox(cc)=min/mean/max SD
VOI <>0  nvox(cc)=min/mean/max SD
VOI >0 nvox(cc)=min/mean/max SD
 
Would you please explain what is the difference ?

and I would like to batch this but I didn't find any guide... 
Thank you
Isabelle