condition mean min max ZT0-3 2.903375 2.884545 2.922205 ZT4-7 2.6136 2.6136 2.6136 ZT8-11 3.0893550000000003 3.0893550000000003 3.0893550000000003 ZT12-15 0 0 0 ZT16-19 3.86597 3.86597 3.86597 ZT20-23 3.38516 3.38516 3.38516