Table 1.

Summary statistics for datasets and fitted SITAR models for the six time intervals in 3172 boys.

Time interval	Number of heights	Number of heights per child (mode)	Proportion of time gaps of one time interval (%)	Degrees of freedom for spline curve	Residual standard deviation (cm)	Variance explained (%)	Mean age at peak height velocity (years)	Mean peak height velocity (cm/year)	Size random effect SD (cm)	Timing random effect SD (%)	Intensity random effect SD (%)
All	128 679	42	—	6	0.74	98.7	14.4	9.6	6.0	6.6	15
2 months	62 965	19	41	6	0.76	98.7	14.4	9.5	6.0	6.6	14
3 months	43 542	13	22	6	0.77	98.7	14.4	9.5	5.9	6.5	14
4 months	41 074	12	54	6	0.77	98.7	14.4	9.6	6.0	6.6	14
6 months	41 504	14	96	6	0.77	98.6	14.4	9.6	5.9	6.6	14
1 year	22 237	7	99.5	6	0.80	98.5	14.4	9.7	5.8	6.5	14
2 years	12 049	4	99.9	5	0.92	98.0	14.2	9.7	5.7	6.2	14