condition mean min max ZT0-3 0.44997016666666667 0.0 0.676605 ZT4-7 2.81867 2.81867 2.81867 ZT8-11 3.5903799999999997 3.5903799999999997 3.5903799999999997 ZT12-15 4.0214325 2.283965 5.758900000000001 ZT16-19 3.7129 3.7129 3.7129 ZT20-23 3.5392849999999996 3.5392849999999996 3.5392849999999996