condition mean min max ZT0-3 1.3664163333333335 1.016974 1.72525 ZT4-7 1.2315495 1.2315495 1.2315495 ZT8-11 0.549892 0.549892 0.549892 ZT12-15 0.891302 0.8236985 0.9589055 ZT16-19 1.075443 1.075443 1.075443 ZT20-23 1.8356400000000002 1.8356400000000002 1.8356400000000002