condition mean min max ZT0-3 1.0068341666666667 0.8919045 1.18811 ZT4-7 0.9320615 0.9320615 0.9320615 ZT8-11 0.6679269999999999 0.6679269999999999 0.6679269999999999 ZT12-15 1.7080875 1.602535 1.81364 ZT16-19 0.851696 0.851696 0.851696 ZT20-23 1.752025 1.752025 1.752025