condition mean min max ZT0-3 2.0628425 1.4999 2.625785 ZT4-7 0.876226 0.876226 0.876226 ZT8-11 3.4366399999999997 3.4366399999999997 3.4366399999999997 ZT12-15 0 0 0 ZT16-19 5.09728 5.09728 5.09728 ZT20-23 3.70139 3.70139 3.70139