Thanks Gila for great info.

And this is not the only server we are using. There is one more server which is as follows:

Microsoft SQL Server 2000 - 8.00.2055 (Intel X86) Dec 16 2008 19:46:53 Copyright (c) 1988-2003 Microsoft Corporation Enterprise Edition on Windows NT 5.2 (Build 3790: Service Pack 2)

And DBCC Memorystats give following information:

Stolen1412

Free16

Procedures6884

Inram0

Dirty9236747

Kept0

I/O0

Latched64

Other182