**Table 4.** Intra-class correlations for maturity offset, stature, body mass and YYIR1 by 2- and 4-year intervals.

| Overall (n=21) |
Low (n=7) |
Average (n=7) |
high(n=7) |

2y stability |
ICC |
95% CI |
ICC |
95% CI |
ICC |
95% CI |
ICC |
95% CI |

Maturity OffSet |
.97 |
.95 - .98 |
.97 |
.94 - .98 |
.97 |
.93 - .98 |
.97 |
.54 - .86 |

Stature |
.94 |
.91 - .96 |
.92 |
.86 - .96 |
.95 |
.91 - .98 |
.93 |
.86 - .97 |

Body mass |
.94 |
.92 - .96 |
.95 |
.90 - .98 |
.93 |
.88 - .97 |
.94 |
.88 - .97 |

YYIR1 |
.76 |
.68 - .84 |
.43 |
.18 - .67 |
.68 |
.48 - .82 |
.73 |
.54 - .86 |

| Overall (n=21) |
Low (n=7) |
Average (n=7) |
High (n=7) |

4y stability |
ICC |
95% CI |
ICC |
95% CI |
ICC |
95% CI |
ICC |
95% CI |

Maturity OffSet |
.66 |
.44 - .83 |
.59 |
.12 - .90 |
.74 |
.34 - .94 |
.48 |
.00 - .86 |

Stature |
.57 |
.32 - .78 |
.27 |
-.17 - .71 |
.54 |
.07 - .89 |
.70 |
.28 - .93 |

Body mass |
.75 |
.57 - .88 |
.73 |
.32 - .94 |
.81 |
.47 - .96 |
-.38 |
.09 - .82 |

YYIR1 |
.59 |
.34 - .79 |
.38 |
-.09 - .83 |
.36 |
-.11 - .82 |
-.44 |
.04 - .87 |