ATLANTA — Georgia students' overall performance on the ACT college-entrance exam rose slightly this year, as the number of students taking the test continued to increase.

Students in Georgia had an average composite score of 20.7 on this year's test, an increase over last year's score of 20.6, according to a report released Wednesday.

Georgia students still trailed the national composite score of 21.1 (on a scale of 1 to 36), which was unchanged from the class of 2011. The percentage nationally who earned scores that ACT calculates indicate they're ready for college in all four subjects — English, reading, math and science — was also unchanged at 25 percent.

Georgia made slight gains in the science and reading portions of the test over last year, but declined slightly in math.

The average science score for Georgia students this year was 20.5, compared to 20.3 last year. In reading, Georgia students had an average score of 21 this year, up from 20.8 last year. The average math score for Georgia students fell to 20.6 from last year's 20.7.

"I am pleased to see our students' scores headed in the right direction and the gap closing between Georgia and the national average," state School Superintendent John Barge said in a statement. "I think it is significant that our participation rate on the ACT increased considerably and we still have growth in overall scores."

About 52 percent of Georgia's 2012 graduating class took the test, up from about 47 percent last year.

Traditionally, more Georgia students take the SAT each year, but the number of students taking the ACT is growing.

ACT defines its college readiness benchmarks as the minimum scores that predict a student has a 75 percent chance of earning a C or higher, or a 50 percent chance of earning a B or higher, in a typical first-year college course in that subject.