condition mean min max ZT0-3 27.064933333333332 26.7735 27.2857 ZT4-7 20.0606 20.0606 20.0606 ZT8-11 21.71765 21.71765 21.71765 ZT12-15 25.389625 25.073 25.706249999999997 ZT16-19 28.14295 28.14295 28.14295 ZT20-23 27.3411 27.3411 27.3411