condition mean min max ZT0-3 5.76752 5.76752 5.76752 ZT4-7 3.624695 3.624695 3.624695 ZT8-11 1.873615 1.873615 1.873615 ZT12-15 4.173715 4.173715 4.173715 ZT16-19 11.86828 11.86828 11.86828 ZT20-23 7.78861 7.78861 7.78861