condition mean min max ZT0-3 15.941483333333332 11.24805 18.998649999999998 ZT4-7 11.537700000000001 11.537700000000001 11.537700000000001 ZT8-11 7.74882 7.74882 7.74882 ZT12-15 10.2982875 9.471475000000002 11.1251 ZT16-19 10.458685 10.458685 10.458685 ZT20-23 19.77675 19.77675 19.77675