At the same time, 45 percent of 10th graders, 44 percent of 11th graders and 62 percent of 12th graders were taking early college courses, which offer students a chance to gain college credit before graduating high school, and 78 percent of students scored a 21 or higher on the ACT, a college admissions test.
Illinois tracks several metrics to determine whether students are college-ready. But a high graduation rate isn't always indicative of college readiness. Data shows 26 percent of Naperville Central students who graduated in 2016 and attended Illinois community colleges had to enroll in remedial classes because they weren't prepared for college-level courses.
By state standards, high school freshmen who completed at least 10 semester credits and received no more than one semester failing grade in a core course, which includes English, math, science and social science, are considered on track to graduate, according to the Illinois State Board of Education. The state tracks progress in ninth grade because data has shown a student who is on track after that year is four times more likely to finish high school than a student who isn't on track.
Similarly, the state says graduating seniors who score a 21 or better on the ACT are prepared for college-level work.
On average in the state, 87 percent of freshmen are on track, while 51 percent of seniors scored 21 or higher on the ACT.
The average four-year graduation rate is 85 percent in Illinois.