Dedupe saving not realized

Hi,

Ontap 7-mode 8.2.4P6, df says volume is full. When dedupe savings are checked it says 44% saved, but not reflected in df o/p. Could any one point out what is the reason for this. There are many snapshopts on this volume as old as 40 days.

PROD> df -hg
Filesystem total used avail capacity Mounted on
/vol/proj_vol1/ 3585GB 3568GB 16GB 100% /vol/proj_vol1/
/vol/proj_vol1/.snapshot 1195GB 534GB 660GB 45% /vol/proj_vol1/.snapsh

PROD> df -sg proj_vol1
Filesystem used saved %saved
/vol/proj_vol1/ 3568GB 2856GB 44%