You can track attrition for each event hotel in your system! In the event hotel's "Basics" section, there is a field to enter your attrition rate for the hotel.

On the Summary Page, you can then view your attrition rate by clicking "Show Attrition".

You may notice under the "Attrition Percentage" field on the Event Hotel "The Basics" page a checkbox.

If this box is checked, the attrition calculation in the Summary page will be based on the inventory numbers added to the "Originally Contracted" fields in the Event > Hotel > Room Type > Inventory page. If this box is unchecked, attrition is calculated as Booked Rooms/Allocated Rooms (inventory from the "Total Inventory" line).

Below is the section on the Inventory page where you can add in the "Originally Contracted" inventory numbers: