Report - First order and date of very first purchase by customer

I am trying to create a number order of all of my customers. So if someone signed up 2/10/2011 they may be my very first member of my membership. They would be #1 and so on over the years. The Chicks Connect Members want to have numbers based on when they joined. I am trying to pull a report and give them all numbers. I haven’t found a good way to do this. it is pulling all purchases not just the very first order. Thank you for any help or ideas that you can give me.