The Cohort Graduation Rate is the percentage of a school’s graduation cohort that obtained a regular high school diploma. Each cohort of students is tracked for four years, from entry as first-time 9th grade students through the 12th grade. It is of particular note that students that do not graduate may: 1) still attend school; 2) drop out of school; or 3) complete school—those students that obtain something other than a regular High School diploma; i.e., Certificate of Achievement (special education), GED.