Quest Items Drop Rate

Hi guys!

How do I change the Quest Items drop rate (Scroll of Emperor, etc)?

Thanks.

EDIT:

I am using MuServer Season 2 (Namech Project)

Edit Quest(kor).txt (or Quest(eng).thx ...)

Example:
//Quest Item Item Item Item Monster Monster Drop Quest Quest Add
//Type Type SubType Level Number MinLvl MaxLvl Rate Type SubType Point Msg1 Msg2 Msg3 Msg4 DW DK Elf MG DL SU RF
1 14 23 0 1 45 60 50 200 0 10 0 52 54 55 56 1 1 1 0 0 1 0

50 - it's drop rate.