condition mean min max ZT0-3 1.33432552625 0.970222602 1.6984284505 ZT4-7 1.8661642795000002 1.4636357885 2.2686927705000004 ZT8-11 5.416962397000001 3.5150277545 7.318897039500001 ZT12-15 9.05375535375 8.2695553215 9.837955386 ZT16-19 6.27201089925 5.88608132 6.6579404785 ZT20-23 7.484592027250001 7.1318305765000005 7.837353478000001