Editor's note: This article has been revised to reflect the following correction, which appears in Tuesday's print edition: Portal Elementary School had the greatest improvement of any Bulloch County public school on the Criterion-Referenced Competency Tests, a 21.9-point gain in the percentage passing fifth-grade math from the 2011-12 school year to 2012-13. Because of a reporter's mistake, a front-page article Sunday listed the wrong subject area in which the gain was posted. The Statesboro Herald regrets the error.