condition mean min max ZT0-3 0.8349448333333334 0.16807699999999998 1.6132650000000002 ZT4-7 1.300955 1.300955 1.300955 ZT8-11 2.6658749999999998 2.6658749999999998 2.6658749999999998 ZT12-15 6.4004650000000005 2.6442699999999997 10.15666 ZT16-19 2.76724 2.76724 2.76724 ZT20-23 1.28817 1.28817 1.28817