Table 3. Mean Difference (Years) between Most Advanced and Most Retarded Bones in Each Age Group and Gender Using Two Measurements.

Age (Years)	BoneXpert		Manual GP
	Boys	Girls	Boys	Girls
2–2.99	2.85	1.65	2.62	1.22
3–3.99	2.76	1.80	2.83	1.15
4–4.99	2.19	2.42	2.52	1.72
5–5.99	2.42	2.84	2.62	2.23
6–6.99	2.65	2.73	2.60	2.22
7–7.99	3.04	2.55	2.92	2.53
8–8.99	3.17	2.50	2.90	2.68
9–9.99	3.01	2.86	2.84	2.51
10–10.99	2.85	2.54	2.50	1.78
11–11.99	2.65	2.50	1.90	2.26
12–12.99	2.24	2.87	1.60	2.14
13–13.99	2.20		1.40
Mean	2.58*		2.25†

^*2.58 and ^†2.25 were overall mean for both gender for BoneXpert and Manual GP, respectively. GP = Greulich and Pyle