condition mean min max ZT0-3 33.823966715 31.2201225 36.42781093 ZT4-7 54.8662324975 51.595044375 58.13742062 ZT8-11 41.95701811 36.917518975 46.996517245 ZT12-15 38.9326029725 33.71124653 44.153959415 ZT16-19 87.556475695 69.71981101 105.39314038 ZT20-23 166.580201625 139.12572455 194.0346787