condition mean min max ZT0-3 1.7269616666666665 1.4119199999999998 1.9970149999999998 ZT4-7 0.9513119999999999 0.9513119999999999 0.9513119999999999 ZT8-11 1.4864899999999999 1.4864899999999999 1.4864899999999999 ZT12-15 1.22892575 0.8771285 1.5807229999999999 ZT16-19 1.887985 1.887985 1.887985 ZT20-23 3.3080249999999998 3.3080249999999998 3.3080249999999998