did. Instead, a rotating roster of professors carried out the day-to-day administration duties. The President of the University of Michigan is the principal executive officer of the university. The office was created by the Michigan Constitution of 1850, which also specified that the president was to be appointed by the Regents of the University of Michigan and preside at their meetings, but without a vote. Today, the president's office is at the Ann Arbor campus, and the president has the privilege of living in the President's House, the university's oldest building, located on Central Campus in Ann Arbor. Mark Schlissel was the 14th president of the university and served in that role from July 2014 to January 2022. Schlissel was fired by the board after an investigation determined he "may have been involved in an inappropriate relationship with an employee of the university". Mary Sue Coleman, who previously had served as Michigan's president from 2002 to 2014, is serving as interim president subsequent to Dr. Schlissel's dismissal. There are thirteen undergraduate schools and colleges. By enrollment, the three largest undergraduate units are the College of Literature, Science, and the Arts, the College of Engineering, and the Ross School of Business. At the graduate level, the Rackham Graduate School serves as the central administrative unit of graduate education at the university. There are 18 graduate schools and colleges, the largest of which are the College of Literature, Science, and the Arts, the College of Engineering, the Law School, and the Ross School of Business. Professional degrees are conferred by the Schools of Architecture, Public Health, Dentistry, Law, Medicine, Urban Planning and Pharmacy. The Medical School is partnered with the University of Michigan Health System, which comprises the university's three hospitals, dozens of outpatient clinics, and many centers for medical care, research, and education. Student government Housed in the Michigan Union, the Central Student Government (CSG) is the central student government of the university. With representatives from each of the university's colleges and schools, including graduate students, CSG represents students and manages student funds on the campus. CSG is a 501(c)(3) organization, independent from the University of Michigan. In recent years CSG has organized Airbus, a transportation service between campus and the Detroit Metropolitan Wayne County Airport, and has led the university's efforts to register its student population to vote, with its Voice Your Vote Commission (VYV) registering 10,000 students in 2004.