Tuning Suggestions Needed

My environment is 10.2.0.3 on solaris 10.

I just collected statistics from some of the tables that hasn't had updated statistics for years. I also increased the buffer_cache_size from 64M to 96M. However, my system does seem to improve that much or maybe even got worse. Below are the awr reports:

Begin Snap:     30186 25-Jun-12 10:00:28     1,763      24.2
  End Snap:     30187 25-Jun-12 11:00:54     1,928      25.7
   Elapsed:               60.42 (mins)
   DB Time:              168.97 (mins)

Cache Sizes
~~~~~~~~~~~                       Begin        End
                             ---------- ----------
               Buffer Cache:        96M        96M  Std Block Size:         8K
           Shared Pool Size:       832M       832M      Log Buffer:    14,400K

Load Profile
~~~~~~~~~~~~                            Per Second       Per Transaction
                                   ---------------       ---------------
                  Redo size:             62,716.43             10,749.14
              Logical reads:             29,787.70              5,105.40
              Block changes:                357.52                 61.28
             Physical reads:              5,680.27                973.56