condition mean min max ZT0-3 6.320785 5.44092 7.2006499999999996 ZT4-7 3.553235 3.553235 3.553235 ZT8-11 3.3333399999999997 3.3333399999999997 3.3333399999999997 ZT12-15 0 0 0 ZT16-19 14.8055 14.8055 14.8055 ZT20-23 18.3914 18.3914 18.3914