condition mean min max ZT0-3 1.6725199505 1.54160802 1.803431881 ZT4-7 2.04787747 1.7465113015 2.3492436385 ZT8-11 2.960307457 2.0766952720000003 3.843919642 ZT12-15 4.37821060375 4.0963123995 4.660108808 ZT16-19 3.6704703805 3.0980303859999996 4.242910375 ZT20-23 5.749901011 5.0457922065 6.4540098155