condition mean min max ZT0-3 1.9326433333333335 1.0822850000000002 3.552 ZT4-7 2.04481 2.04481 2.04481 ZT8-11 2.106585 2.106585 2.106585 ZT12-15 3.190095 2.32829 4.0519 ZT16-19 2.0973499999999996 2.0973499999999996 2.0973499999999996 ZT20-23 1.67056 1.67056 1.67056