condition mean min max ZT0-3 1.663115 1.663115 1.663115 ZT4-7 1.5240300000000002 1.5240300000000002 1.5240300000000002 ZT8-11 1.3213650000000001 1.3213650000000001 1.3213650000000001 ZT12-15 2.289815 2.289815 2.289815 ZT16-19 5.43188 5.43188 5.43188 ZT20-23 2.705705 2.705705 2.705705