condition mean min max ZT0-3 2.304342666666667 1.035708 3.59711 ZT4-7 1.8319649999999998 1.8319649999999998 1.8319649999999998 ZT8-11 1.34361 1.34361 1.34361 ZT12-15 4.855975 3.35121 6.36074 ZT16-19 5.890725 5.890725 5.890725 ZT20-23 5.66636 5.66636 5.66636