condition mean min max ZT0-3 1.394725 1.394725 1.394725 ZT4-7 1.5951149999999998 1.5951149999999998 1.5951149999999998 ZT8-11 0.754256 0.754256 0.754256 ZT12-15 0.6645035 0.6645035 0.6645035 ZT16-19 0.9132965 0.9132965 0.9132965 ZT20-23 1.079352 1.079352 1.079352