How much aggregate thruput can be expected on a G network?

I have an omni connected to xr2 which is installed on an RB433.
There are roughly 20 clients associated to this ap. The ap is running wireless G only.
I am curious as to what amount of total throughput can be expected with this set up. What is it dependent on? Number of clients, etc.?

in ptmp max is ~15mbps total in 20Mhz channel. I get about 12-14mbps.

its depent of the size of packet .. when u use 1500bytes packet you can get up to 25 Mbps on TCP but if you use 64byte up to 17 18Mbps..without routing..

AP RB333 ---- nanostation CPE 20Mhz channels