Table I.

Demographic characteristics of the study participants.

Characteristic	No. of participants	%
Age, years
15-20	365	70.6
21-25	152	29.4
Total	517	100.0
Sex
Female	328	63.4
Male	181	35.0
Othera	8	1.5
Education level
No superior studies/apprentice	111	21.5
High school	198	38.3
University student	208	40.2

^aOther indicates that the female or male sex was not checked in the questionnaire, but instead the box ‘other’ was checked.