condition mean min max ZT0-3 17.405698 17.405698 17.405698 ZT4-7 20.952784 20.952784 20.952784 ZT8-11 19.213767 19.213767 19.213767 ZT12-15 20.7425785 20.7425785 20.7425785 ZT16-19 19.030409 19.030409 19.030409 ZT20-23 15.269800499999999 15.269800499999999 15.269800499999999