calculation of storage reduction and efficency ratio for isi quota cli output doesn't make sense

Hi gurus,

    Below is the output from my F200. It really confusing that FSLogical size is 2.33T, Physcial is 2.35T, but storage recution and efficency ratio looks so high.  Could anyone help me how Isilon caluculate it? Thanks.

IS-1# isi quota quotas  view /ifs/fnarray/astne directory
                        Path: /ifs/fnarray/astne
                        Type: directory
                   Snapshots: No
                    Enforced: Yes
                   Container: Yes
                      Linked: No
                      Labels:
                 Description:
                       Usage
                           Files: 863872
         Physical(With Overhead): 2.35T
        FSPhysical(Deduplicated): 1.28T
         FSLogical(W/O Overhead): 2.33T
        AppLogical(ApparentSize): 2.33T
                   ShadowLogical: -
                    PhysicalData: 178.49G
                      Protection: 54.03G
     Reduction(Logical/Data): 2.47 : 1
Efficiency(Logical/Physical): 1.82 : 1
                        Over: -
               Thresholds On: fslogicalsize
              ReadyToEnforce: Yes
                  Thresholds
                   Hard Threshold: 10.10T