Gov. Nathan Deal and his Office of Student Achievement announced Tuesday that 187 public schools qualify as being the highest performers or having the greatest gains in Georgia in 2015.

Nearly half are in core metro Atlanta school districts. They were in 51 school districts, with nine schools in Atlanta, 21 in Cobb County (plus two in the city of Marietta), 13 in DeKalb County (plus one in the city of Decatur), 23 in Fulton and 13 in Gwinnett (plus two in the city of Buford).

The results are based on the state’s College and Career Ready Performance Index. The highest performers were those that ranked at or above the 93rd percentile for their “achievement” score, while the greatest gainers ranked that way on their “progress” score, in each case based on an average over three years.

The student achievement office also released this new school reports website.