condition mean min max ZT0-3 3.509895 3.1955 3.82429 ZT4-7 3.03726 3.03726 3.03726 ZT8-11 3.31762 3.31762 3.31762 ZT12-15 0 0 0 ZT16-19 1.205755 1.205755 1.205755 ZT20-23 1.640025 1.640025 1.640025