Table 2.

Mean and standard deviation (SD) for AP scores at age 3, 7, 10 and 12 in the total sample and in the genotyped sample

		Total sample						Genotyped sample						F	p
		Boys			Girls			Boys			Girls
		Valid N	Mean	SD	Valid N	Mean	SD	Valid N	Mean	SD	Valid N	Mean	SD
Age 3	Mo	14331	2.9	2.2	14386	2.5	2.1	537	3.0	2.2	545	2.7	2.3	2.28	0.13
	Fa	9418	2.8	2.1	9448	2.5	2.1	370	2.9	2.2	363	2.7	2.1	2.06	0.15
Age 7	Mo	8461	3.4	3.0	8645	2.5	2.8	495	3.3	2.8	519	2.5	2.7	<1	0.92
	Fa	6132	3.0	2.7	6193	2.1	2.6	414	3.1	2.7	448	2.3	2.5	2.91	0.09
Age 10	Mo	5332	3.5	3.1	5698	2.4	2.9	501	3.5	2.9	505	2.7	2.8	1.09	0.30
	Fa	3782	3.0	2.8	4013	2.1	2.7	410	3.1	2.7	402	2.3	2.6	1.95	0.16
Age 12	Mo	3495	3.2	3.0	3668	2.1	2.7	453	3.1	2.8	483	2.3	2.7	<1	0.64
	Fa	2535	2.8	2.8	2679	1.9	2.5	371	2.7	2.7	398	1.9	2.5	<1	0.48

In the last 2 columns the statistics for the comparison of AP scores between total and genotyped sample