condition mean min max ZT0-3 0.76326989 0.697126185 0.829413595 ZT4-7 1.40132814725 0.8517816434999999 1.9508746510000001 ZT8-11 3.6838201807499997 2.5175148729999997 4.8501254885 ZT12-15 3.927848742 3.8638989365 3.9917985475 ZT16-19 2.91859071525 2.7939781330000004 3.0432032975 ZT20-23 3.30048819725 2.561444996 4.0395313985