My DC242 use too much toner ???

Hi,
I've just got a second-hand Xerox DC242 with Freeflow Print Server.
After printing 250prints x A3 (Color Mode: Normal in Freeflow), the toner decreased 10% yellow and 10% magenta.

I'm using a Xerox WC7775 and I know it is impossible
Is my DC242 took too much toner or I have to change my setting in freeflow?

(sorry for my poor English)

 

I don't know if it's accurate enough that you can gauge usage by 10%. See how it is over a few sets of toner on average before you jump to conclusions.

 

It's what DC242 said in supplies menu, before and after, it decreased 10% toner.
I hope it gauged wrong but in my WC7775, it's quite accurate.