Here is an organization that can provide information on local disability statistics:

Governor's Council On Developmental Disabilities
2 Peachtree Street
Suite 210
Atlanta, GA   30303
404-657-2126 (voice)
404-657-2133 (TTD)
1-888-275-4233 GA Only (v/tty)
Homepage: http://www.gcdd.org/
Contact: Beth Spinning, Program Director
Email: bspinning@dhr.state.ga.us