Hi. The whole area of the state of Queretaro is wonderful. I dont have information about the number of expats in the area but I can tell you that it is a great place to live. I am not retired but my mom is and she loves it here. We live in a town named Tequisquiapan. We are 30 min from the city of Queretaro. It is a small colonial town just right for retireing. There are some interesting living options in Tequisquiapan for retirees. I can give you more info if you wish.
Victor