Illinois Board of Higher Education (IBHE) enrollment and demographic data (1996-2006)
Source: IBHE Data Book
Table I-2: Total Fall Enrollments by Gender, Race or National Origin, and Type of Institution, and Level of Instruction http://legacy.ibhe.org/IBHEDatabook/ChapterI/Table%20I-2.aspx
One file (.csv) was downloaded for each year (1996 - 2016). No data were available for 2013. The data are very untidy, but at least they're consistently untidy.
These data are publicly available and represent all institutions of higher education in Illinois. As an example, Northern Illinois University is explored in detail. Replace "Northern Illinois University" with the name of another school to explore a different college or university.