Table 1.

Age and sex distribution ($\overline{x}\hspace{0.17em}\pm \hspace{0.17em}s$).

	2006	2007	2008	2009	2010	2011
Male	136 (54.4%)	157 (53.6%)	193 (53.8%)	204 (54.1%)	227 (52.5%)	286 (56.3%)
Female	114 (45.6%)	136 (46.4%)	166 (46.2%)	173 (45.9%)	205 (47.5%)	222 (43.7%)
Age	9.53 ± 4.11	9.44 ± 4.42	9.77 ± 4.24	9.75 ± 4.43	9.62 ± 4.40	9.28 ± 4.25
Onset age	3.76 ± 3.58	3.59 ± 3.67	3.84 ± 3.23	3.97 ± 3.42	3.70 ± 3.29	3.44 ± 3.21