Table I.

Mean ± standard deviation (SD) ages of the participants and the number of subjects in each group.

		Male		Female		Male + female
Groups	Age range, years	n	Age, years (mean ± SD)	n	Age, years (mean ± SD)	n	Age, years (mean ± SD)
Group I	20–29	162	27.8±1.1	175	24.8±3.3	337	26.3±2.9
Group II	30–39	151	36.5±3.3	168	32.1±2.1	319	34.3±3.0
Group III	40–49	149	45.2±3.9	166	43.8±5.1	315	44,5±4.6
Group IV	50–59	163	56.1±4.1	148	56.9±3.9	311	56.5±4.1
Group V	60–69	80	66.9±4.1	91	64.9±4.0	171	65.9±4.0
Total	20–69	705	46.5±13.8	748	44.5±13.4	1,453	45.5±13.5