condition mean min max ZT0-3 4.671425 3.36036 5.7129449999999995 ZT4-7 3.571195 3.571195 3.571195 ZT8-11 4.331055 4.331055 4.331055 ZT12-15 6.19384 5.67316 6.71452 ZT16-19 5.880775 5.880775 5.880775 ZT20-23 6.59441 6.59441 6.59441