Table 1.

Basic distribution of the social variables

	girls		boys		girls & boys
	N	%	N	%	N	%
sex	637	50.4	628	49.6	1265	100
parental education
- high	363	57.0	328	52.2	691	54.6
- medium	140	22.0	157	25.0	297	23.5
- low	112	17.6	128	20.4	240	19.0
- missing value	22	3.5	15	2.4	37	2.9
household income
- high	202	31.7	181	28.8	383	30.2
- medium	126	19.8	118	18.8	244	19.3
- low	68	10.7	67	10.7	135	10.7
- missing value	241	37.8	262	41.7	503	39.8
parental working status
- not unemployed	541	84.9	529	84.2	1070	84.6
- unemployed	77	12.1	82	13.1	159	12.6
- missing value	19	3.0	17	2.7	36	2.8
nationality
- (exclusively) German	471	73.9	440	70.1	911	72.0
- others	165	25.9	183	29.1	348	27.5
- missing value	1	0.16	5	0.8	6	0.5
single parenthood
- others	547	85.9	524	83.4	1071	84.7
- single parent	84	13.2	97	15.5	181	14.3
- missing value	6	0.9	7	1.1	13	1.0