The average duration of students' enrollment and the average age of graduates differ among different fields of study. The average duration of students' enrollment in 1986 was 7.6 years for universities. 5.9 years for teacher training colleges, and 6.3 years for colleges of arts and music. The average age of graduates was 28.4 for universities, 26.9 for teacher training colleges, and 26.9 for colleges of arts and music. No definite courses of study leading to a doctorate have been institutionalized.
Doctoral candidates have only to pass the examination of the dissertation they have prepared.
It takes usually three to five years to ear a doctorate. In some universities experimental courses have recently been introduced in which a group of doctoral candidates conduct joint study and research. The number of students and researchers conferred a Habilitation was about 1,.000 in a year, and their average age in 1988 was 39.8. Formerly there were professors, assistant professors and lecturers at universities. All these positions have been renamed as professors, which are classified into C4.