Table 1.

Sample characteristics as percentages.

	Primary school (n = 81) Mean age: 8.98 years (SD 0.39)	Middle school (n = 72) Mean age: 12.14 years (SD 0.61)	High school (n = 73) Mean age: 15.10 years (SD 0.38)	Total (N = 226)
GENDER
Boys	59.3	55.6	52.1	55.8
Girls	40.7	44.4	47.9	44.2
AREA
Urban	46.9	48.6	52.1	49.1
Rural	53.1	51.4	47.9	50.9
IMMIGRANT STATUS
Native	79.0	76.4	90.4	81.9
Immigrant	21.0	23.6	9.6	18.1
SES*
Middle-low	27.2	27.8	6.8	20.8
Middle	54.3	65.3	48.0	55.8
Middle-high	16.1	6.9	45.2	22.5

Note:

^*Two missing data in primary school.