Question : CISCO PIX 525: understanding statistics

Hello,
we are hosting a meeting for 250 people.
We've hosted meetings of this kind for a long time and 6Mbps has always been more than enough to support every user needs.
We have a CISCO PIX 525 between our network and the hotel router.
The configuration is very simple: one rule allow any any from inside to outside and dynamic NAT for all clients.
Today (first day of the meeting) we are already using the whole bandwidth.
We've extended the bandwidth to 10Mbps and it seems a bit better but we are always on the edge.
The ASDM Dashboard shows an average usage of 7.5Mbps for both internal and external NIC.
The "Connection Statistics" show an average of 3200 connections.
If I look in the Top usage statistics I see nothing outstanding: top 10 usage users "consume" on average between 40 and 12 kbps.
I need to understand if this is a normal behaviour due to our 250 people connections or if it could be related to something else.

Attachments:

DeviceDash.JPG (218 KB) (File Type Details) 

Device Dashboard

FirewallDash.JPG (216 KB) (File Type Details) 

Firewall Dashboard

Answer : CISCO PIX 525: understanding statistics

Sorry guys,
apparently our firewall and the switch it is connected to were not synced. Once we forced the communication to full/duplex it seems to be better.

Thanks anyway,
Roberto.