Table 4.

Percentages of Girls With Secondary Sexual Characteristics at Sexual Maturity Stage 2 or Greater by Age and Race*

Age
(yr)
Breast DevelopmentPubic HairAxillary Hair
Af.-Am.WhiteAf.-Am.WhiteAf.-Am.White
32.07  (1.03–4.74)0.70  (0.45–1.17)1.03  (0.42–3.38)0.26  (0.13–0.61)0.70  (0.25–2.98)0.09  (0.03–0.38)
42.77  (1.50–5.64)0.67  (0.43–1.10)5.19  (3.27–8.61)0.24  (0.12–0.55)1.40  (0.62–3.89)0.12  (0.05–0.40)
52.40  (1.15–5.93)1.54  (1.13–2.21)3.37  (1.76–7.16)0.42  (0.24–0.80)0.50  (0.15–3.60)0.08  (0.03–0.36)
66.35  (3.45–12.58)2.93  (2.22–3.95)9.52  (5.74–16.37)1.40  (0.94–2.18)1.64  (0.59–6.77)0.27  (0.12–0.76)
715.44  (10.51–22.78)4.97  (3.88–6.45)17.65  (12.33–25.21)2.75  (1.98–3.93)6.67  (3.74–12.68)0.54  (0.27–1.26)
837.76  (30.31–46.03)10.50  (9.00–12.30)34.27  (27.08–42.49)7.67  (6.38–9.25)16.79  (11.64–24.24)1.75  (1.19–2.66)
962.61  (53.37–70.82)32.11  (29.39–35.00)62.61  (53.37–70.82)20.04  (17.77–22.58)40.18  (31.64–49.54)6.43  (5.13–8.14)
1080.18  (71.47–86.33)61.51  (58.66–64.27)85.59  (77.44–90.71)46.43  (43.56–49.32)49.55  (40.41–58.72)20.69  (18.46–23.17)
1196.03  (90.39–98.11)85.36  (83.12–87.30)95.24  (89.38–97.61)74.27  (71.58–76.75)81.30  (73.19–87.02)41.96  (39.05–44.95)
1298.90  (92.32–99.67)95.97  (94.44–97.03)98.90  (92.32–99.67)92.15  (90.17–93.68)93.41  (85.56–96.69)68.25  (65.09–71.22)
  • * Followed by 95% confidence intervals in parentheses.