Figures my first post would be about something other than quilting (I'm new to the quilting world). I did win the business plan competition in business school though (not for a quilt shop). A good sources of this type of information are trade organizations. Most shops are unlikely to share any real number for you. One source for quilt shops is
https://fabshopnet.com/ Hopefully you can find something there. They have an article on shop benchmarks that may be helpful