condition mean min max ZT0-3 1.8886416666666666 1.6930399999999999 2.12441 ZT4-7 1.441125 1.441125 1.441125 ZT8-11 2.5880349999999996 2.5880349999999996 2.5880349999999996 ZT12-15 2.7696275000000004 2.408675 3.13058 ZT16-19 1.9881799999999998 1.9881799999999998 1.9881799999999998 ZT20-23 2.01986 2.01986 2.01986