condition mean min max ZT0-3 26.99495 24.222 29.767899999999997 ZT4-7 25.62125 25.62125 25.62125 ZT8-11 20.983800000000002 20.983800000000002 20.983800000000002 ZT12-15 0 0 0 ZT16-19 26.54605 26.54605 26.54605 ZT20-23 29.194049999999997 29.194049999999997 29.194049999999997