condition mean min max ZT0-3 8.2197521405 7.8111478100000005 8.628356471 ZT4-7 9.417833761499999 9.179042688 9.656624835 ZT8-11 10.956557791333335 10.411011399333335 11.502104183333334 ZT12-15 10.670954809666668 10.513923926 10.827985693333334 ZT16-19 11.62310223 10.93535877 12.310845689999999 ZT20-23 11.415589125 10.281566793333333 12.549611456666666