maximum no of guestOS can i install?

Hi all,

I am using DELL2950 with 16GB of RAM. I installed ESX3.5. On top of it i installed 16 WinXp VMs each of which 1GB of RAM.

So, all of my 16GB RAM occupied by GuestOS. And Most of the VM's are on, all the time. Now i want to increase guestOS number to 32.

Can i able to increase VMs in the current hardware structure? or How ESX3.5 handles memory? I saw while configuring that we can have upto 4095 guestOS at the max.

Thanks in advance.