condition mean min max ZT0-3 218.562889 218.562889 218.562889 ZT4-7 368.8362625 368.8362625 368.8362625 ZT8-11 514.524451 514.524451 514.524451 ZT12-15 435.7813725 435.7813725 435.7813725 ZT16-19 276.1619645 276.1619645 276.1619645 ZT20-23 235.68386950000001 235.68386950000001 235.68386950000001