Distribution of subjects with regard to age, gender and education.

NOTE:* Education was ordinally measured with 1 = Compulsory schooling not completed (less than 9 years of school) or special school; 2 = Completed compulsory schooling (9–10 years of school); 3 = Completed vocational training (10–12 years of school); 4 = Highschool graduation with university entrance exam (12–13 years of school); 5 = University or college degree. Distribution of subjects with regard to age, gender and education.