Powershell scripts for Isilon performance stats

in screenshot 5, how come individual nodes stats do not add up to the number in All row ?

Thanks

looks like %used is an average while other stats are a sum of individual nodes

isi statistics system --nodes -d
 Node   CPU   SMB   FTP  HTTP ISCSI   NFS Total NetIn NetOut DiskIn DiskOut
  LNN %Used   B/s   B/s   B/s   B/s   B/s   B/s   B/s    B/s    B/s     B/s
  All   1.3   0.0   0.0   0.0   0.0   0.0   0.0   11K   1.1K   159K     0.0
    1   0.0   0.0   0.0   0.0   0.0   0.0   0.0  1.8K  235.6    48K     0.0
    2   3.4   0.0   0.0   0.0   0.0   0.0   0.0  2.4K  431.0    0.0     0.0
    3   0.3   0.0   0.0   0.0   0.0   0.0   0.0  1.6K   24.8    16K     0.0
    4   0.2   0.0   0.0   0.0   0.0   0.0   0.0  1.7K    0.0    48K     0.0
    5   3.7   0.0   0.0   0.0   0.0   0.0   0.0  2.0K  374.4    48K     0.0
    6   0.0   0.0   0.0   0.0   0.0   0.0   0.0  1.5K   70.2    0.0     0.0

This must be something internal to how the stats are calculated by way of some Isilon internal logic.  Possibly, each stat is calculated individually and the total can represent the individual components at different time slices.  The scripts don't do any data manipulation.

I would have to forward this one to the Isilon group to see why the "isi statistics system --nodes -d" demonstrates what you see.