After inline upgrade of SEP client 12.1.5 to 12.1.6 directory is not deleted ?

Hi,

I've just performed manual upgrade of SEP client 12.1.5 to 12.1.6  in one of my Windows Server 2008 R2 using Domain Administrator account.

But from C:\ProgramData\Symantec\Symantec Endpoint Protection\12.1.5337.5000.105​ somehow the old 12.1 directory is still quite big 1.6 GB+

I cannot delete it even after I did smc -stop and verified the server has been rebooted.

Therefore the SEP client direcotry is now 2.45 GB (2,634,235,904 bytes) so is that normal with just 1 definition update ?