Enrolments (sometimes called FTE's or Full Time Equivalent Enrolments) are counts of students enrolled in courses, and are usually reported by fiscal year for budgeting purposes. Fiscal year 2015 ends April 30, 2015.
In fiscal year 2014 (ended April 30, 2014) there were:
Overview of Arts & Science Departments, fiscal years 2013-2014 [5p, PDF], in Excel [.xls, Excel 2003]
Summary for each Arts and Science Department: Equivalent Full Time Faculty (EFTS), student course section counts, student counts, and Full Time On Campus undergraduate concentrator counts, and graduate student counts.
These values may also be validated by counts using standard PeopleSoft queries.