condition mean min max ZT0-3 22.543451 22.543451 22.543451 ZT4-7 20.670544 20.670544 20.670544 ZT8-11 20.998593 20.998593 20.998593 ZT12-15 16.927725000000002 16.927725000000002 16.927725000000002 ZT16-19 18.589008999999997 18.589008999999997 18.589008999999997 ZT20-23 15.779460499999999 15.779460499999999 15.779460499999999