condition mean min max ZT0-3 2.3375583333333334 1.532705 2.7978300000000003 ZT4-7 1.58237 1.58237 1.58237 ZT8-11 1.94827 1.94827 1.94827 ZT12-15 3.890805 3.3880100000000004 4.393599999999999 ZT16-19 2.298225 2.298225 2.298225 ZT20-23 4.065075 4.065075 4.065075