condition mean min max ZT0-3 9.5653075 8.823675 10.30694 ZT4-7 9.61262 9.61262 9.61262 ZT8-11 8.92833 8.92833 8.92833 ZT12-15 0 0 0 ZT16-19 14.1894 14.1894 14.1894 ZT20-23 15.620449999999998 15.620449999999998 15.620449999999998