condition mean min max ZT0-3 24.783387635 23.78578639 25.780988880000002 ZT4-7 8.856343022 7.5763504535 10.1363355905 ZT8-11 8.351328057 6.071802015499999 10.6308540985 ZT12-15 7.4319626455000005 6.467528995 8.396396296 ZT16-19 7.0989931429999995 6.7385950195 7.459391266499999 ZT20-23 9.181398932250001 9.1651204925 9.197677372000001