condition mean min max ZT0-3 21.83665 21.83665 21.83665 ZT4-7 16.969549999999998 16.969549999999998 16.969549999999998 ZT8-11 22.1186 22.1186 22.1186 ZT12-15 25.117449999999998 25.117449999999998 25.117449999999998 ZT16-19 27.7342 27.7342 27.7342 ZT20-23 21.3778 21.3778 21.3778