condition mean min max ZT0-3 18.162843345 17.212446 19.11324069 ZT4-7 7.16472463875 4.8894433445 9.440005933 ZT8-11 1.915704309 1.8967027295 1.9347058885 ZT12-15 5.631661028 3.5781746055 7.6851474505 ZT16-19 9.38076631 8.0677830855 10.6937495345 ZT20-23 11.195243189 10.174443837999998 12.21604254