That's for Fulton County as a whole. Lewis's district only takes up part of the county.
The majority of the 5th District is also the majority of Fulton County. The District includes a part of DeKalb and Clayton counties and excludes a small part of northern Fulton County. The GBI reports are by county, not congressional district.
http://share.myfultoncountyga.us/datashare/fultoncounty/maps/CongressionalDistricts_ep_v1.pdf