condition mean min max ZT0-3 21.554316666666665 20.4814 23.4746 ZT4-7 21.0806 21.0806 21.0806 ZT8-11 14.06175 14.06175 14.06175 ZT12-15 20.466025000000002 19.677300000000002 21.25475 ZT16-19 21.8355 21.8355 21.8355 ZT20-23 22.84885 22.84885 22.84885