condition mean min max ZT0-3 3.98222 1.678065 6.181035 ZT4-7 1.35858 1.35858 1.35858 ZT8-11 3.007095 3.007095 3.007095 ZT12-15 4.50361 4.306075 4.701145 ZT16-19 5.064195 5.064195 5.064195 ZT20-23 7.130515 7.130515 7.130515