condition mean min max ZT0-3 17.053303333333332 9.18451 23.175150000000002 ZT4-7 6.90177 6.90177 6.90177 ZT8-11 12.11945 12.11945 12.11945 ZT12-15 21.174475 20.907600000000002 21.44135 ZT16-19 19.3858 19.3858 19.3858 ZT20-23 24.87945 24.87945 24.87945