[Freesurfer] mean thickness over hemisphere in stats file

Dear experts,

please excuse my question, I'm a beginner. I really searched for an answer in the archive, but I couldn't find out what I was doing wrong.

I would like to write the mean cortical thickness of a hemisphere in the stats file. I read one can do that by using -m thickness. Where in the command line do I have to put it? I tried various versions, but it doesn't work.

This would be the command:

aparcstats2table --hemi rh --parc aparc --meas thickness --tablefile "directory"//"filename" --m thickness --subjects 1 2 3 4 SUBJECTS_DIR : "directory"

Where do I include the -m thickness option? Or do I have to add something else?

Thank you very much for your help, Ines