*2.2. Participants*

## 2.2.1. 2011 Sample

In total, 1924 students (total number in the enrolled schools) were invited to participate in the study, and n= 1239 responded, with an age range of 13–18 years (response rate 64%). The sample included 634 (51.2%) girls and 603 (48.7%) boys; 2 respondents did not identify their sex (Table 1).


**Table 1.** Demographic characteristics for the adolescent sample aged 13–20 years.

#### 2.2.2. 2016 Sample

In total, 1906 students (total number in the enrolled schools) were invited to participate in the study, and 1282 completed the questionnaire (response rate of 67%). The age range of the included sample was restricted to 13–20 years, reducing the sample size to n = 1233. In the sample, 580 (47%) were girls and 644 (52.2%) were boys; 9 respondents did not report their sex (Table 1).

#### 2.2.3. 2022 Sample

In total, 1538 students (total number in the enrolled schools) were invited to participate in the study, and 311 completed the questionnaire (response rate 20.2%). The sample consisted of 167 (53.7%) girls and 141 (45.3%) boys; 3 respondents did not identify their sex (Table 1). The age range of the sample was 13–20 years.
