Veritas Enterprise Vault performance issue

Dears

i came Across Dtrace scripts and used performance scripts and what i saw in the logs seems not clear for me as per below logs my decompressed message size is smaller than my compressed message size.

which is totally not logic for me, any ideas?

CSavesetPersist::PackSavesetBytes Completed compression step. hr=Success  (0)|Uncompressed size:79360 Compressed size:79401 Elapsed:0.00 (secs)
CSavesetPersist::PackSavesetBytes Completed verification decompression step. hr=Success  (0)|Compressed size:79401 Uncompressed size:79360 Elapsed:0.00 (secs)