The 2015 state average for students in public schools was 70 percent.
For RIHS, its college enrollment rate remains unchanged since 2014.
The data, collected by the National Student Clearinghouse, includes two and four year colleges.
Enrollment at RIHS in 2015 was 1,851. 402 (21.72 percent) were seniors.
Also according to ISBE, 24.6 percent of RIHS seniors were "college ready" in 2015, versus an average of 46 percent statewide.
All students who score a 21 on the ACT qualify as "college ready."
RIHS students did better on reading (22.4 percent) and English (39.6 percent) and worse on math (17.0) and science (17.2).
Only 9.3 percent of RIHS students were college ready in all four subjects, according to ISBE.