condition mean min max ZT0-3 214.693515 214.693515 214.693515 ZT4-7 230.827853 230.827853 230.827853 ZT8-11 206.916881 206.916881 206.916881 ZT12-15 227.85694 227.85694 227.85694 ZT16-19 211.5905395 211.5905395 211.5905395 ZT20-23 148.0945955 148.0945955 148.0945955