WBAP/KLIF – A free health clinic that organizers like to refer to as “the world’s largest doctor’s office” will take over the Kay Bailey Hutchison Center in Dallas Saturday. The National Association of Free and Charitable Clinics says Dallas County has one of the country’s highest rates of residents without health insurance. Organizers expect to serve more than a thousand patients between the time the doors open at 9:00 am and the time they close at 3:00 pm. They believe they could serve a thousand more if they had another 30 doctors and nurses.