condition mean min max ZT0-3 1.6146516666666666 1.46054 1.77721 ZT4-7 1.63004 1.63004 1.63004 ZT8-11 1.34015 1.34015 1.34015 ZT12-15 1.5471225 1.29989 1.794355 ZT16-19 1.227075 1.227075 1.227075 ZT20-23 1.526795 1.526795 1.526795