condition mean min max ZT0-3 3.48867 3.48867 3.48867 ZT4-7 3.65561 3.65561 3.65561 ZT8-11 3.000135 3.000135 3.000135 ZT12-15 3.5933149999999996 3.5933149999999996 3.5933149999999996 ZT16-19 5.518 5.518 5.518 ZT20-23 3.59453 3.59453 3.59453