condition mean min max ZT0-3 17.671333333333333 11.6278 25.06295 ZT4-7 19.494549999999997 19.494549999999997 19.494549999999997 ZT8-11 27.539450000000002 27.539450000000002 27.539450000000002 ZT12-15 36.5239 35.94125 37.10655 ZT16-19 38.4128 38.4128 38.4128 ZT20-23 16.1963 16.1963 16.1963