condition mean min max ZT0-3 271.695677 271.695677 271.695677 ZT4-7 270.36100600000003 270.36100600000003 270.36100600000003 ZT8-11 268.098816 268.098816 268.098816 ZT12-15 300.408016 300.408016 300.408016 ZT16-19 336.109571 336.109571 336.109571 ZT20-23 327.101889 327.101889 327.101889