condition mean min max ZT0-3 2.375695 2.10356 2.64783 ZT4-7 3.42035 3.42035 3.42035 ZT8-11 3.708385 3.708385 3.708385 ZT12-15 0 0 0 ZT16-19 2.28152 2.28152 2.28152 ZT20-23 3.0829050000000002 3.0829050000000002 3.0829050000000002