The Georgia Department of Education has released the the school-level ACT Scores: http://www.gadoe.org/External-Affairs-and-Policy/communications/Pages/PressReleaseDetails.aspx?PressView=default&pid=558
The following schools exceeded or met the National Composite Average (21.0) for the ACT:
Chamblee Charter High School (24.9)
DeKalb Early College Academy (21.6)
DeKalb School of the Arts (24.8)
Dunwoody High School (24.3)
Lakeside High School (23.4)
