condition mean min max ZT0-3 63.336559 63.336559 63.336559 ZT4-7 53.475458 53.475458 53.475458 ZT8-11 85.325515 85.325515 85.325515 ZT12-15 71.32389 71.32389 71.32389 ZT16-19 137.177322 137.177322 137.177322 ZT20-23 102.526671 102.526671 102.526671