Table 2. Mean and standard deviation of normal controls for the (SH+SD)/D ratio of the C5 vertebra.

Age group	<1	1–2	2–3	3–4	4–5	5–6	6–7	7–8	8–9	9–10	10–11	11–12	12–13	13–14	14–15	15–16	16–17	17–18	18–19	19–20	20–21
Mean	1.05	1.10	1.09	1.20	1.21	1.43	1.37	1.47	1.33	1.47	1.50	1.53	1.51	1.57	1.69	1.86	1.76	1.73	1.71	1.78	1.86
SD	0.13	0.15	0.15	0.13	0.11	0.18	0.18	0.17	0.19	0.18	0.16	0.18	0.20	0.19	0.12	0.16	0.22	0.22	0.23	0.24	0.25
N	11	21	17	13	6	13	25	19	20	17	16	17	14	20	16	21	23	31	28	38	20

SD denotes standard deviation; N, number of control subjects; SH, height of the spinous process; SD, depth of the spinous process; D, depth of the vertebral body.