condition mean min max ZT0-3 15.7568 15.7568 15.7568 ZT4-7 6.90132 6.90132 6.90132 ZT8-11 5.630825 5.630825 5.630825 ZT12-15 6.336925 6.336925 6.336925 ZT16-19 30.875349999999997 30.875349999999997 30.875349999999997 ZT20-23 22.37695 22.37695 22.37695