Table 2.
Age at menarche (95% CI) of girls aged 9–18 among 24 ethnic minorities from 1985 to 2010
| Ethnic minorities | 1985 | 1991 | 1995 | 2000 | 2005 | 2010 | Difference 1985 to 2010 | Months of decline per decade |
|---|---|---|---|---|---|---|---|---|
| Mongolian (urban) | 13.68 (13.50–13.87) | 13.73 (13.32–14.15) | – | 12.96 (12.76–13.44) | 12.51 (12.02–12.94) | 12.26 (12.06–12.46) | −1.42* | 6.82 |
| Mongolian (rural) | 14.06 (13.90–14.25) | 13.95 (13.56–14.35) | – | 13.44 (12.00–14.66) | 12.93 (12.76–13.09) | 12.52 (12.36–12.68) | −1.54* | 7.39 |
| Mongolian (combined) | 13.95 (13.82–14.07) | 13.93 (13.53–14.35) | – | 13.27 (12.47–14.01) | 12.78 (12.51–13.04) | 12.44 (12.03–12.84) | −1.51* | 7.25 |
| Hui (urban) | 13.60 (13.42–13.79) | 13.22 (12.98–13.46) | 13.14 (12.92–13.35) | 13.03 (12.88–13.25) | 12.90 (12.70–13.10) | 13.03 (12.46–13.56) | −0.57* | 2.74 |
| Hui (rural) | 13.95 (13.83–14.07) | 13.33 (13.02–13.65) | 13.73 (13.53–13.94) | 13.90 (13.47–14.30) | 13.43 (13.12–13.73) | 13.20 (11.88–14.68) | −0.75 | 3.60 |
| Hui (combined) | 13.73 (13.55–13.91) | 13.38 (13.15–13.60) | 13.46 (13.30–13.62) | 13.44 (12.63–14.18) | 13.28 (13.00–13.54) | 13.09 (12.42–13.76) | −0.64* | 3.07 |
| Uighur (urban) | 14.21 (14.04–14.38) | 14.03 (13.84–14.22) | 13.57 (13.36–13.78) | 13.47 (13.26–13.72) | – | 13.56 (12.92–14.12) | −0.65* | 3.12 |
| Uighur (rural) | 14.44 (14.25–14.63) | 14.29 (14.03–14.54) | 14.49 (14.28–14.70) | 13.48 (13.29–13.77) | – | 13.78 (13.40–14.14) | −0.66* | 3.17 |
| Uighur (combined) | 14.42 (14.29–14.54) | 14.17 (14.00–14.35) | 13.92 (13.77–14.08) | 13.48 (13.30–13.80) | – | 13.67 (13.34–13.99) | −0.75* | 3.60 |
| Kazakh (Hasake) | 14.54 (14.39–14.69) | – | 13.82 (13.64–14.02) | – | – | 12.85 (12.70–13.00) | −1.69* | 8.11 |
| Kirghiz | 14.72 (14.49–14.95) | – | 14.65 (14.44–14.86) | 13.86 (13.67–14.03) | – | 13.40 (12.81–13.96) | −1.32* | 6.34 |
| Zhuang (urban) | 13.35 (13.18–13.53) | 12.97 (12.64–13.30) | 13.11 (12.92–13.30) | 12.58 (11.90–13.22) | 13.02 (12.69–13.33) | 12.26 (12.11–12.41) | −1.09* | 5.23 |
| Zhuang (rural) | 13.20 (12.97–14.43) | 13.12 (12.58–13.39) | 14.68 (14.41–14.96) | 13.12 (12.20–13.89) | 12.42 (11.84–12.99) | 12.79 (12.30–13.28) | −0.41* | 1.97 |
| Zhuang (combined) | 13.21 (13.05–13.36) | 13.02 (12.83–13.21) | 13.83 (13.66–14.00) | 12.86 (12.52–13.18) | 12.71 (12.38–13.04) | 12.52 (12.33–12.70) | −0.69* | 3.31 |
| Yao | 14.43 (14.22–14.64) | – | 13.59 (13.38–13.79) | 13.54 (13.24–13.95) | 12.67 (11.75–13.52) | 13.41 (12.81–13.99) | −1.02* | 4.90 |
| Korean (urban) | 13.22 (13.07–13.38) | 12.92 (12.69–13.15) | 12.92 (12.67–13.16) | 12.30 (12.07–12.61) | 12.25 (11.93–12.56) | 11.94 (11.71–12.16) | −1.28* | 6.14 |
| Korean (rural) | 13.56 (13.39–13.73) | 13.34 (12.99–13.69) | 12.50 (12.28–12.72) | 12.87 (12.54–13.19) | 12.43 (13.32–12.54) | 11.65 (11.32–11.97) | −1.91* | 9.17 |
| Korean (combined) | 13.36 (13.25–13.47) | 13.14 (12.93–13.35) | 12.75 (12.58–12.92) | 12.59 (12.21–12.96) | 12.35 (12.21–12.49) | 11.79 (11.68–11.89) | −1.57* | 7.54 |
| Tibetan | 13.63 (13.42–13.84) | 13.73 (13.35–14.13) | 13.72 (13.52–13.92) | 13.04 (12.72–13.39) | 13.42 (12.84–14.00) | 13.12 (11.41–14.81) | −0.51 | 2.45 |
| Miao | 13.71 (13.53–13.89) | 13.15 (12.78–13.54) | 13.54 (13.33–13.75) | 12.95 (12.43–13.39) | 13.00 (12.83–13.18) | 13.36 (12.99–13.72) | −0.35 | 1.68 |
| Buyi | 13.91 (13.68–14.13) | 13.57 (13.15–14.01) | 13.37 (13.08–13.66) | 13.25 (12.93–13.69) | 13.12 (10.70–15.60) | 13.26 (13.01–13.51) | −0.65* | 3.12 |
| Dong | 14.26 (14.07–14.45) | 13.21 (12.95–13.47) | 13.50 (13.31–13.68) | 13.41 (13.08–13.80) | 13.32 (13.16–13.48) | 12.91 (12.48–13.34) | −1.35* | 6.48 |
| Tujia | 14.05 (13.90–14.20) | – | – | 13.63 (13.47–13.78) | 11.90 (11.36–12.40) | 13.02 (12.27–13.72) | −1.03* | 4.94 |
| Bai | 13.91 (13.73–14.09) | 13.15 (12.89–13.24) | – | 13.44 (13.07–13.84) | 12.89 (11.85–13.89) | 12.79 (11.77–13.74) | −1.12* | 5.38 |
| Hani | 14.42 (14.25–14.58) | 17.17 (15.73–18.84) | 13.40 (13.24–13.57) | – | 13.37 (12.88–13.84) | 13.12 (12.46–13.78) | −1.30* | 6.24 |
| Dai | 14.27 (14.12–14.43) | 13.43 (13.12–13.74) | – | 13.39 (13.09–13.72) | 13.24 (13.08–13.39) | 12.73 (12.47–12.98) | −1.54* | 7.39 |
| Lisu | 14.83 (14.66–14.99) | – | 13.10 (12.88–13.34) | – | 13.60 (13.43–13.76) | 13.04 (12.39–13.68) | −1.79* | 8.59 |
| Wa (Va) | 13.85 (13.63–14.08) | – | 12.56 (12.34–12.78) | – | 13.17 (11.77–14.58) | 13.06 (12.91–13.20) | −0.79* | 3.79 |
| Naxi (Nakhi) | 13.35 (13.20–13.51) | 13.09 (12.88–13.31) | 13.04 (12.86–13.22) | – | 11.97 (11.83–12.11) | 12.64 (12.48–12.79) | −0.71* | 3.41 |
| Li | 13.10 (12.94–13.26) | 13.02 (12.79–13.24) | 13.04 (12.84–13.24) | 13.23 (12.87–13.56) | – | 12.95 (12.80–13.09) | −0.15 | 0.72 |
| Tu | 14.22 (14.02–14.43) | 14.34 (13.83–14.86) | 14.03 (13.80–14.26) | 13.63 (13.46–13.81) | 13.61 (12.89–14.33) | 13.40 (12.76–13.99) | −0.82* | 3.94 |
| Sala | 14.47 (14.18–14.76) | 14.45 (14.09–14.81) | 14.26 (13.87–14.67) | 14.07 (13.82–14.31) | 14.30 (14.15–14.44) | 14.32 (14.02–14.61) | −0.15 | 0.72 |
| Qiang | 14.07 (13.91–14.23) | – | 13.81 (13.63–13.99) | 12.49 (11.67–13.11) | 13.42 (13.28–13.56) | 12.85 (12.71–13.00) | −1.22* | 5.86 |
| Yi | 13.80 (13.60–14.01) | – | – | – | – | 13.74 (13.47–14.00) | −0.06 | 0.29 |
*
p<0.05 CI, confidence interval.