condition mean min max ZT0-3 6794.8 6794.8 6794.8 ZT4-7 6367.4 6367.4 6367.4 ZT8-11 6739.700000000001 6739.700000000001 6739.700000000001 ZT12-15 7349.299999999999 7349.299999999999 7349.299999999999 ZT16-19 7915.55 7915.55 7915.55 ZT20-23 7851.4 7851.4 7851.4