condition mean min max ZT0-3 18.5884623 9.309277105 27.867647495 ZT4-7 69.3823332025 55.081471629999996 83.683194775 ZT8-11 189.2165748575 144.483250615 233.94989909999998 ZT12-15 141.34309935 103.8155706 178.87062809999998 ZT16-19 102.6087774075 101.71607232 103.501482495 ZT20-23 52.217147059999995 26.61963396 77.81466015999999