Topas - Memory Stats

I have four AIX 5.3 logical partitions running on a p550. On three of the
LPARs, the percentage statistics under the Memory heading in topas add up
to close to 100%. The other LPAR has the following stats...

Memory
Real,MB 7872
% Comp 52.9
% Noncomp 7.5
% Client 0.5

Please note that this LPAR was recently rebooted.

Can someone please explain these numbers to me. Should I be concerned that
these percentages are not close to 100 percent? Is it because the LPAR was
very recently rebooted (about a half hour ago)?