condition mean min max ZT0-3 0.7424970000000001 0.5168295 0.8666365 ZT4-7 0.6589795 0.6589795 0.6589795 ZT8-11 0.849443 0.849443 0.849443 ZT12-15 1.2769225 1.093055 1.4607899999999998 ZT16-19 1.87639 1.87639 1.87639 ZT20-23 1.7512349999999999 1.7512349999999999 1.7512349999999999