condition mean min max ZT0-3 172.681662 172.681662 172.681662 ZT4-7 167.268054 167.268054 167.268054 ZT8-11 191.3956865 191.3956865 191.3956865 ZT12-15 255.45349149999998 255.45349149999998 255.45349149999998 ZT16-19 241.404224 241.404224 241.404224 ZT20-23 178.69205399999998 178.69205399999998 178.69205399999998