Hello, Mary,
Other than the Association of Children's Museums and the AAM, I would check into the research done by Susan Wilkening Consulting. Her team gathers data on a wide range of topics and issues. The URL, below, takes you to a web page on which you will find various reports – each one presented in a clear, inviting and conversational way.
https://www.wilkeningconsulting.com/data-stories.html
Terrie
------------------------------
Terrie Nolinske, Ph.D.
Principal, TNI Consultants LLC
813. 973. 2102
tni@tniconsultants.comTampa, FL
------------------------------