Table 1. Specific age distribution over groups and subgroups.

subgroup	group	n	mean age	minimum	maximum	SD
1–5 years	Group 1	8	3.3	2	5	1.5
	Group 2	10	2	0	5	1.4
6–10 years	Group 1	4	9.3	9	10	0.5
	Group 2	7	7.4	6	10	1.5
11–15 years	Group 1	14	13.1	11	15	1.5
	Group 2	11	13.5	11	15	1
16–20 years	Group 1	13	17.2	16	19	1.1
	Group 2	16	18.6	16	20	1.2
21–25 years	Group 1	8	22.6	21	25	1.2
	Group 2	24	23.4	21	25	1.4
26–30 years	Group 1	6	27.7	26	30	1.6
	Group 2	30	27.6	26	30	1.4

Shown is the age distribution for both CT protocols examined (“group”) as well as the age-related subgroups (“subgroup”).