I use a multi-bookings event published on my Microsoft bookings page for an exercise class. The number of spaces available are restricted and for the most part this works well. However, the multi-booking event is open to all my customers, and given event has restricted number of places, I would like my oldest customers who have been with me from the beginning to have priority or opportunity to book before all the rest. How can I achieve this? How do I give them (original customers) opportunity to book before everyone else? Would welcome any help of suggestions with this issue please! Thank you in advance.