condition mean min max ZT0-3 33.078325 32.68875 33.4679 ZT4-7 35.5389 35.5389 35.5389 ZT8-11 34.2786 34.2786 34.2786 ZT12-15 0 0 0 ZT16-19 51.28235 51.28235 51.28235 ZT20-23 34.62985 34.62985 34.62985