The map below depicts the four-year cohort graduation rate for students who began ninth grade in North Carolina in 2002. That is, it is the state’s best estimate of the percentage of ninth graders who received high school diplomas four years later. The overall four-year graduation rate for this group of students was 68.3 percent statewide. At the school district level, the graduation rate ranged from 43.7 percent at Lexington City Schools to 90.2 percent at Chapel Hill-Carrboro Schools.
The cohort graduation rate was first reported by the Department of Public Instruction (DPI) in February 2007. It was arrived at by first determining the students who entered ninth grade for the first time in the 2002-03 school year, adding students who transferred in to that cohort over the next three years, and subtracting students from that cohort who died or transferred. (This is the denominator.) Next, the students in the denominator who received a diploma by June 30, 2006 were identified. (This is the numerator.) The numerator was divided by the denominator to determine the graduation rate.
DPI has noted that, since 15 percent of ninth graders are required to repeat ninth grade, some students take more than four years to graduate. However, DPI also reported an "on-time" graduation rate of 98.7 percent, meaning that only 2.3 percent of graduates spend more than four years in high school. As a result, when DPI released a five-year cohort graduation rate this summer, the rate increased only slightly, from 68.3 percent to 70.3 percent.