System Of A Down - Drugs Bass

Alright, this is my first tab, so please give me suggestions if it's not accurate.

I know this song isn't played on bass either, but if you're a bassist and you want to 
the bassic riffs, here you go:

Riff 1 (x1):

F|-----------------------------------------------------|
C|-----------------------------------------------------|
G|-----------------------------------------------------|
C|-7-7-9--9--9--7-7-9--9--9--7-7-9--9--9--7-7-9--9--9--|

Riff 2 (x2):

F|------------------------------------------------------|----|
C|------------------------------------------------------|----|
G|------------------------------------------------------|----|
C|-7-7-9--9--9--7-7-9--9--9--9-9-12--12--7--7--9--9--9--|-9--|<--2nd time

Riff 3 (x2):

F|---------------------------|
C|---------------------------|
G|---------------------------|
C|-12--12--7--7--9--9--9--9--|

Thanks for checking out my tab, please rate and comment :)