Completion is calculated based on the number of years since the student was first enrolled in higher education. In tables showing students beginning individual studies, completion time is calculated based on the number of years since the student enrolled on the particular study programme for the first time. Students are followed in two years more than normal study progression (N+2). The reference year used for entering higher education will vary due to the duration of study. Students who do not complete within the expected completion time may have studied part time, or had to interrupt their studies during the programme, or changed course or completed another programme earlier.