condition mean min max ZT0-3 2.912555 2.87646 2.9486499999999998 ZT4-7 3.02443 3.02443 3.02443 ZT8-11 2.90326 2.90326 2.90326 ZT12-15 0 0 0 ZT16-19 5.27642 5.27642 5.27642 ZT20-23 4.19971 4.19971 4.19971