condition mean min max ZT0-3 7.371065 7.347545 7.394585 ZT4-7 7.917145 7.917145 7.917145 ZT8-11 5.75288 5.75288 5.75288 ZT12-15 0 0 0 ZT16-19 7.1528849999999995 7.1528849999999995 7.1528849999999995 ZT20-23 7.33037 7.33037 7.33037