condition mean min max ZT0-3 1.1101605 0.797701 1.42262 ZT4-7 0.3976895 0.3976895 0.3976895 ZT8-11 1.45288 1.45288 1.45288 ZT12-15 0 0 0 ZT16-19 1.960655 1.960655 1.960655 ZT20-23 1.6233499999999998 1.6233499999999998 1.6233499999999998