condition mean min max ZT0-3 2.4937449999999997 2.4937449999999997 2.4937449999999997 ZT4-7 3.913935 3.913935 3.913935 ZT8-11 4.32244 4.32244 4.32244 ZT12-15 2.3467599999999997 2.3467599999999997 2.3467599999999997 ZT16-19 4.915 4.915 4.915 ZT20-23 4.35281 4.35281 4.35281