condition mean min max ZT0-3 2.631 2.384615 2.9195599999999997 ZT4-7 0.8289545 0.8289545 0.8289545 ZT8-11 1.558695 1.558695 1.558695 ZT12-15 2.843375 2.39963 3.28712 ZT16-19 4.4517 4.4517 4.4517 ZT20-23 3.511795 3.511795 3.511795