condition mean min max ZT0-3 2.9577549999999997 2.8129299999999997 3.1025799999999997 ZT4-7 4.57132 4.57132 4.57132 ZT8-11 5.4171700000000005 5.4171700000000005 5.4171700000000005 ZT12-15 0 0 0 ZT16-19 5.555745 5.555745 5.555745 ZT20-23 5.65561 5.65561 5.65561