condition mean min max ZT0-3 1.779455 1.33178 2.22713 ZT4-7 2.002945 2.002945 2.002945 ZT8-11 2.14431 2.14431 2.14431 ZT12-15 0 0 0 ZT16-19 1.964865 1.964865 1.964865 ZT20-23 1.9723249999999999 1.9723249999999999 1.9723249999999999