condition mean min max ZT0-3 20.1476 18.28285 21.345750000000002 ZT4-7 22.3531 22.3531 22.3531 ZT8-11 21.892899999999997 21.892899999999997 21.892899999999997 ZT12-15 28.118625 23.34515 32.8921 ZT16-19 26.40885 26.40885 26.40885 ZT20-23 28.626350000000002 28.626350000000002 28.626350000000002